Bio


Recent years have seen unprecedented motivation for the emergence of new energy technologies. Global dependence on fossil fuels, however, will persist until alternate technologies can compete economically. We must develop means to produce energy (or energy carriers) from renewable sources and then convert them to work as efficiently and cleanly as possible. Catalysis is energy conversion, and the Jaramillo laboratory focuses on fundamental catalytic processes occurring on solid-state surfaces in both the production and consumption of energy. Chemical-to-electrical and electrical-to-chemical energy conversion are at the core of the research. Nanoparticles, metals, alloys, sulfides, nitrides, carbides, phosphides, oxides, and biomimetic organo-metallic complexes comprise the toolkit of materials that can help change the energy landscape. Tailoring catalyst surfaces to fit the chemistry is our primary challenge.

Academic Appointments


Administrative Appointments


  • Director, SUNCAT Center for Interface Science and Catalysis (2018 - Present)
  • Deputy Director, SUNCAT Center for Interface Science and Catalysis (2014 - 2018)

Professional Education


  • PhD, University of California, Santa Barbara (2004)
  • MS, University of California, Santa Barbara, Chemical Engineering (2000)
  • BS, Stanford, Chemical Engineering (1998)

2020-21 Courses


Stanford Advisees


All Publications


  • Ni5Ga3 catalysts for CO2 reduction to methanol: Exploring the role of Ga surface oxidation/reduction on catalytic activity APPLIED CATALYSIS B-ENVIRONMENTAL Gallo, A., Snider, J. L., Sokaras, D., Nordlund, D., Kroll, T., Ogasawara, H., Kovarik, L., Duyar, M. S., Jaramillo, T. F. 2020; 267
  • A cyclic electrochemical strategy to produce acetylene from CO2, CH4, or alternative carbon sources SUSTAINABLE ENERGY & FUELS McEnaney, J. M., Rohr, B. A., Nielander, A. C., Singh, A. R., King, L. A., Norskov, J. K., Jaramillo, T. F. 2020; 4 (6): 2752–59

    View details for DOI 10.1039/c9se00799g

    View details for Web of Science ID 000539290400013

  • Nitride or Oxynitride? Elucidating the Composition-Activity Relationships in Molybdenum Nitride Electrocatalysts for the Oxygen Reduction Reaction CHEMISTRY OF MATERIALS Kreider, M. E., Stevens, M., Liu, Y., Patel, A. M., Statt, M. J., Gibbons, B. M., Gallo, A., Ben-Naim, M., Mehta, A., Davis, R. C., Ievlev, A., Norskov, J. K., Sinclair, R., King, L. A., Jaramillo, T. F. 2020; 32 (7): 2946–60
  • In Situ X-Ray Absorption Spectroscopy Disentangles the Roles of Copper and Silver in a Bimetallic Catalyst for the Oxygen Reduction Reaction CHEMISTRY OF MATERIALS Gibbons, B. M., Wette, M., Stevens, M., Davis, R. C., Siahrostami, S., Kreider, M., Mehta, A., Higgins, D. C., Clemens, B. M., Jaramillo, T. F. 2020; 32 (5): 1819–27
  • Electrolyte Engineering for Efficient Electrochemical Nitrate Reduction to Ammonia on a Titanium Electrode ACS SUSTAINABLE CHEMISTRY & ENGINEERING McEnaney, J. M., Blair, S. J., Nielander, A. C., Schwalbe, J. A., Koshy, D. M., Cargnello, M., Jaramillo, T. F. 2020; 8 (7): 2672–81
  • Using Microenvironments to Control Reactivity in CO2 Electrocatalysis JOULE Hahn, C., Jaramillo, T. F. 2020; 4 (2): 292–94
  • A Combined Theory-Experiment Analysis of the Surface Species in Lithium-Mediated NH3 Electrosynthesis CHEMELECTROCHEM Schwalbe, J. A., Statt, M. J., Chosy, C., Singh, A. R., Rohr, B. A., Nielander, A. C., Andersen, S. Z., McEnaney, J. M., Baker, J. G., Jaramillo, T. F., Norskov, J. K., Cargnello, M. 2020
  • Selective reduction of CO to acetaldehyde with CuAg electrocatalysts. Proceedings of the National Academy of Sciences of the United States of America Wang, L., Higgins, D. C., Ji, Y., Morales-Guio, C. G., Chan, K., Hahn, C., Jaramillo, T. F. 2020

    Abstract

    Electrochemical CO reduction can serve as a sequential step in the transformation of CO2 into multicarbon fuels and chemicals. In this study, we provide insights on how to steer selectivity for CO reduction almost exclusively toward a single multicarbon oxygenate by carefully controlling the catalyst composition and its surrounding reaction conditions. Under alkaline reaction conditions, we demonstrate that planar CuAg electrodes can reduce CO to acetaldehyde with over 50% Faradaic efficiency and over 90% selectivity on a carbon basis at a modest electrode potential of -0.536 V vs. the reversible hydrogen electrode. The Faradaic efficiency to acetaldehyde was further enhanced to 70% by increasing the roughness factor of the CuAg electrode. Density functional theory calculations indicate that Ag ad-atoms on Cu weaken the binding energy of the reduced acetaldehyde intermediate and inhibit its further reduction to ethanol, demonstrating that the improved selectivity to acetaldehyde is due to the electronic effect from Ag incorporation. These findings will aid in the design of catalysts that are able to guide complex reaction networks and achieve high selectivity for the desired product.

    View details for DOI 10.1073/pnas.1821683117

    View details for PubMedID 31980521

  • Morphology control of metal-modified zirconium phosphate support structures for the oxygen evolution reaction. Dalton transactions (Cambridge, England : 2003) Ramos-Garces, M. V., Sanchez, J., La Luz-Rivera, K., Del Toro-Pedrosa, D. E., Jaramillo, T. F., Colon, J. L. 2020

    Abstract

    The electrochemical oxygen evolution reaction (OER) is the half-cell reaction for many clean-energy production technologies, including water electrolyzers and metal-air batteries. However, its sluggish kinetics hinders the performance of those technologies, impeding them from broader implementation. Recently, we reported the use of zirconium phosphate (ZrP) as a support for transition metal catalysts for the oxygen evolution reaction (OER). These catalysts achieve promising overpotentials with high mass activities. Herein, we synthesize ZrP structures with controlled morphology: hexagonal platelets, rods, cubes, and spheres, and subsequently modify them with Co(ii) and Ni(ii) cations to assess their electrochemcial OER behavior. Through inductively coupled plasma mass-spectrometry measurements, the maximum ion exchange capacity is found to vary based on the morphology of the ZrP structure and cation selection. Trends in geometric current density and mass activity as a function of cation selection are discussed. We find that the loading and coverage of cobalt and nickel species on the ZrP supports are key factors that control OER performance.

    View details for DOI 10.1039/c9dt04135d

    View details for PubMedID 31894216

  • A Spin Coating Method To Deposit Iridium-Based Catalysts onto Silicon for Water Oxidation Photoanodes. ACS applied materials & interfaces Ben-Naim, M., Palm, D. W., Strickler, A. L., Nielander, A. C., Sanchez, J., King, L. A., Higgins, D. C., Jaramillo, T. F. 2020

    Abstract

    Silicon has shown promise for use as a small band gap (1.1 eV) absorber material in photoelectrochemical (PEC) water splitting. However, the limited stability of silicon in acidic electrolyte requires the use of protection strategies coupled with catalysts. Herein, spin coating is used as a versatile method to directly coat silicon photoanodes with an IrO x oxygen evolution reaction (OER) catalyst, reducing the processing complexity compared to conventional fabrication schemes. Biphasic strontium chloride/iridium oxide (SrCl2:IrO x ) catalysts are also developed, and both catalysts form photoactive junctions with silicon and demonstrate high photoanode activity. The iridium oxide photoanode displays a photocurrent onset at 1.06 V vs reversible hydrogen electrode (RHE), while the SrCl2:IrO x photoanode onsets earlier at 0.96 V vs RHE. The differing potentials are consistent with the observed photovoltages of 0.43 and 0.53 V for the IrO x and SrCl2:IrO x , respectively. By measuring the oxidation of a reversible redox couple, Fe(CN)63-/4-, we compare the charge carrier extraction of the devices and show that the addition of SrCl2 to the IrO x catalyst improves the silicon-electrolyte interface compared to pure IrO x . However, the durability of the strontium-containing photoanode remains a challenge, with its photocurrent density decreasing by 90% over 4 h. The IrO x photoanode, on the other hand, maintained a stable photocurrent density over this timescale. Characterization of the as-prepared and post-tested material structure via Auger electron spectroscopy identifies catalyst film cracking and delamination as the primary failure modes. We propose that improvements to catalyst adhesion should further the viability of spin coating as a technique for photoanode preparation.

    View details for DOI 10.1021/acsami.9b20099

    View details for PubMedID 31971770

  • Double layer charging driven carbon dioxide adsorption limits the rate of electrochemical carbon dioxide reduction on Gold. Nature communications Ringe, S., Morales-Guio, C. G., Chen, L. D., Fields, M., Jaramillo, T. F., Hahn, C., Chan, K. 2020; 11 (1): 33

    Abstract

    Electrochemical CO[Formula: see text] reduction is a potential route to the sustainable production of valuable fuels and chemicals. Here, we perform CO[Formula: see text] reduction experiments on Gold at neutral to acidic pH values to elucidate the long-standing controversy surrounding the rate-limiting step. We find the CO production rate to be invariant with pH on a Standard Hydrogen Electrode scale and conclude that it is limited by the CO[Formula: see text] adsorption step. We present a new multi-scale modeling scheme that integrates ab initio reaction kinetics with mass transport simulations, explicitly considering the charged electric double layer. The model reproduces the experimental CO polarization curve and reveals the rate-limiting step to be *COOH to *CO at low overpotentials, CO[Formula: see text] adsorption at intermediate ones, and CO[Formula: see text] mass transport at high overpotentials. Finally, we show the Tafel slope to arise from the electrostatic interaction between the dipole of *CO[Formula: see text] and the interfacial field. This work highlights the importance of surface charging for electrochemical kinetics and mass transport.

    View details for DOI 10.1038/s41467-019-13777-z

    View details for PubMedID 31911585

  • Understanding the Origin of Highly Selective CO2 Electroreduction to CO on Ni, N-doped Carbon Catalysts. Angewandte Chemie (International ed. in English) Koshy, D., Chen, S., Lee, D. U., Burke Stevens, M., Abdellah, A., Dull, S., Chen, G., Nordlund, D., Gallo, A., Hahn, C., Higgins, D. C., Bao, Z., Jaramillo, T. 2020

    Abstract

    Ni,N-doped carbon catalysts have shown promising catalytic performance for CO 2 electroreduction (CO 2 R) to CO; this activity has been attributed to the presence of nitrogen-coordinated, single metal atom active sites. However, experimentally confirming Ni-N bonding and correlating CO 2 reduction (CO 2 R) activity to these species has remained a fundamental challenge. We synthesized polyacrylonitrile-derived Ni, N-doped carbon electrocatalysts (Ni-PACN) with a range of pyrolysis temperatures and Ni loadings and correlated their electrochemical activity with extensive physiochemical characterization to rigorously address the origin of activity in these materials. We found that the CO- 2 R to CO partial current density increased with increased Ni content before plateauing at 2 wt% which suggests a dispersed Ni active site. These dispersed active sites were investigated by hard and soft x-ray spectroscopy, which revealed that pyrrolic nitrogen ligands selectively bind Ni atoms in a distorted square-planar geometry that strongly resembles the active sites of molecular metal-porphyrin catalysts.

    View details for DOI 10.1002/anie.201912857

    View details for PubMedID 31919948

  • The Materials Research Platform: Defining the Requirements from User Stories MATTER Aykol, M., Hummelshoj, J. S., Anapolsky, A., Aoyagi, K., Bazant, M. Z., Bligaard, T., Braatz, R. D., Broderick, S., Cogswell, D., Dagdelen, J., Drisdell, W., Garcia, E., Garikipati, K., Gavini, V., Gent, W. E., Giordano, L., Gomes, C. P., Gomez-Bombarelli, R., Gopal, C., Gregoire, J. M., Grossman, J. C., Herring, P., Hung, L., Jaramillo, T. F., King, L., Kwon, H., Maekawa, R., Minor, A. M., Montoya, J. H., Mueller, T., Ophus, C., Rajan, K., Ramprasad, R., Rohr, B., Schweigert, D., Shao-Horn, Y., Suga, Y., Suram, S. K., Viswanathan, V., Whitacre, J. F., Willard, A. P., Wodo, O., Wolverton, C., Storey, B. D. 2019; 1 (6): 1433–38
  • A non-precious metal hydrogen catalyst in a commercial polymer electrolyte membrane electrolyser. Nature nanotechnology King, L. A., Hubert, M. A., Capuano, C., Manco, J., Danilovic, N., Valle, E., Hellstern, T. R., Ayers, K., Jaramillo, T. F. 2019

    Abstract

    We demonstrate the translation of a low-cost, non-precious metal cobalt phosphide (CoP) catalyst from 1cm2 lab-scale experiments to a commercial-scale 86cm2 polymer electrolyte membrane (PEM) electrolyser. A two-step bulk synthesis was adopted to produce CoP on a high-surface-area carbon support that was readily integrated into an industrial PEM electrolyser fabrication process. The performance of the CoP was compared head to head with a platinum-based PEM under the same operating conditions (400psi, 50°C). CoP was found to be active and stable, operating at 1.86Acm-2 for>1,700h of continuous hydrogen production while providing substantial material cost savings relative to platinum. This work illustrates a potential pathway for non-precious hydrogen evolution catalysts developed in past decades to translate to commercial applications.

    View details for DOI 10.1038/s41565-019-0550-7

    View details for PubMedID 31611657

  • Transition Metal Arsenide Catalysts for the Hydrogen Evolution Reaction JOURNAL OF PHYSICAL CHEMISTRY C Gauthier, J. A., King, L. A., Stults, F., Flores, R. A., Kibsgaard, J., Regmi, Y. N., Chan, K., Jaramillo, T. F. 2019; 123 (39): 24007–12
  • Surface Engineering of 3D Gas Diffusion Electrodes for High-Performance H-2 Production with Nonprecious Metal Catalysts ADVANCED ENERGY MATERIALS Sanchez, J., Hellstern, T. R., King, L. A., Jaramillo, T. F. 2019
  • Aqueous Electrochemical Reduction of Carbon Dioxide and Carbon Monoxide into Methanol with Cobalt Phthalocyanine. Angewandte Chemie (International ed. in English) Boutin, E., Wang, M., Lin, J. C., Mesnage, M., Mendoza, D., Lassalle-Kaiser, B., Hahn, C., Jaramillo, T., Robert, M. 2019

    Abstract

    CO2 conversion into valuable molecules has emerged as a field of intensive investigation, with the aim of ultimately developing scalable technologies for making fuels using renewable sources of energy. Electrochemically reduction into CO and formate getting closer from industrial maturity, the challenge is now to obtain more reduced products like methanol, an already commercialized fuel. At the contrary, literature is really scarce on the matter, and even more when using molecular catalyst. Here, we demonstrate that cobalt phthalocyanine, a long known catalyst for the CO2 to CO electrochemical step, can also catalyse the reaction from CO2 or CO until methanol in aqueous electrolyte, at ambient temperature and atmospheric pressure. Detailed studies identified formaldehyde as key intermediate and unexpected pH effect on selectivity. This paves the way for establishing a sequential process where CO2 is first converted to CO and is subsequently used as reactant to produce methanol. In optimal conditions, CO2 could be catalyzed to CH3OH with a 19.5% global Faradaic efficiency and 7.5% chemical selectivity.

    View details for DOI 10.1002/anie.201909257

    View details for PubMedID 31496012

  • Understanding vapor-fed carbon dioxide reduction at the gas diffusion electrode and electrolyte interface Using flow-electrolyte systems Lee, D., Koshy, D., Abiose, K., Corral, D., Wang, L., Higgins, D., Hahn, C., Jaramillo, T. AMER CHEMICAL SOC. 2019
  • Promoting reliable electrocatalytic N2 reduction Nielander, A., McEnaney, J., Blair, S., Schwalbe, J., Baker, J., Jaramillo, T. AMER CHEMICAL SOC. 2019
  • Electro-Oxidation of Methane on Platinum under Ambient Conditions ACS CATALYSIS Boyd, M. J., Latimer, A. A., Dickens, C. F., Nielander, A. C., Hahn, C., Norskov, J. K., Higgins, D. C., Jaramillo, T. F. 2019; 9 (8): 7578–87
  • Electrochemically converting carbon monoxide to liquid fuels by directing selectivity with electrode surface area NATURE CATALYSIS Wang, L., Nitopi, S., Wong, A. B., Snider, J. L., Nielander, A. C., Morales-Guio, C. G., Orazov, M., Higgins, D. C., Hahn, C., Jaramillo, T. F. 2019; 2 (8): 702–8
  • Crystalline Strontium Iridate Particle Catalysts for Enhanced Oxygen Evolution in Acid ACS APPLIED ENERGY MATERIALS Strickler, A. L., Higgins, D., Jaramillo, T. F. 2019; 2 (8): 5490–98
  • Interfacial engineering of gallium indium phosphide photoelectrodes for hydrogen evolution with precious metal and non-precious metal based catalysts JOURNAL OF MATERIALS CHEMISTRY A Britto, R. J., Young, J. L., Yang, Y., Steiner, M. A., LaFehr, D. T., Friedman, D. J., Beard, M., Deutsch, T. G., Jaramillo, T. F. 2019; 7 (28): 16821–32

    View details for DOI 10.1039/c9ta05247j

    View details for Web of Science ID 000476599900020

  • Precious Metal-Free Nickel Nitride Catalyst for the Oxygen Reduction Reaction. ACS applied materials & interfaces Kreider, M. E., Gallo, A., Back, S., Liu, Y., Siahrostami, S., Nordlund, D., Sinclair, R., Norskov, J. K., King, L. A., Jaramillo, T. F. 2019

    Abstract

    With promising activity and stability for the oxygen reduction reaction (ORR), transition metal nitrides are an interesting class of non-platinum group catalysts for polymer electrolyte membrane fuel cells. Here, we report an active thin-film nickel nitride catalyst synthesized through a reactive sputtering method. In rotating disk electrode testing in a 0.1 M HClO4 electrolyte, the crystalline nickel nitride film achieved high activity and selectivity to four-electron ORR. It also exhibited good stability during 10 and 40 h chronoamperometry measurements in acid and alkaline electrolyte, respectively. A combined experiment-theory approach, with detailed ex situ materials characterization and density functional theory calculations, provides insight into the structure of the catalyst and its surface during catalysis. Design strategies for activity and stability improvement through alloying and nanostructuring are discussed.

    View details for DOI 10.1021/acsami.9b07116

    View details for PubMedID 31310093

  • A Versatile Method for Ammonia Detection in a Range of Relevant Electrolytes via Direct Nuclear Magnetic Resonance Techniques ACS CATALYSIS Nielander, A. C., McEnaney, J. M., Schwalbe, J. A., Baker, J. G., Blair, S. J., Wang, L., Pelton, J. G., Andersen, S. Z., Enemark-Rasmussen, K., Colic, V., Yang, S., Bent, S. F., Cargnello, M., Kibsgaard, J., Vesborg, P. K., Chorkendorff, I., Jaramillo, T. F. 2019; 9 (7): 5797–5802
  • A rigorous electrochemical ammonia synthesis protocol with quantitative isotope measurements. Nature Andersen, S. Z., Colic, V., Yang, S., Schwalbe, J. A., Nielander, A. C., McEnaney, J. M., Enemark-Rasmussen, K., Baker, J. G., Singh, A. R., Rohr, B. A., Statt, M. J., Blair, S. J., Mezzavilla, S., Kibsgaard, J., Vesborg, P. C., Cargnello, M., Bent, S. F., Jaramillo, T. F., Stephens, I. E., Norskov, J. K., Chorkendorff, I. 2019

    Abstract

    The electrochemical synthesis of ammonia from nitrogen under mild conditions and using renewable electricity is in principle an attractive alternative1-4 to the demanding, energy-intense Haber-Bosch process, which dominates industrial ammonia production. However, the electrochemical alternative faces considerable scientific and technical challenges5,6 and most experimental studies reported thus far achieve only low selectivities and conversions. In fact, the amount of ammonia produced is usually so small that it is difficult to firmly attribute it to electrochemical nitrogen fixation7-9 and exclude contamination due to ammonia that is either present in air, human breath or ion-conducting membranes9, or generated from labile nitrogen-containing compounds (for example, nitrates, amines, nitrites and nitrogen oxides) that are typically present in the nitrogen gas stream10, in the atmosphere or even the catalyst itself. Although these many and varied sources of potential experimental artefacts are beginning to be recognized and dealt with11,12, concerted efforts to develop effective electrochemical nitrogen reduction processes would benefit from benchmarking protocols for the reaction and from a standardized set of control experiments to identify and then eliminate or quantify contamination sources. Here we put forward such a rigorous procedure that, by making essential use of 15N2, allows us to reliably detect and quantify the electroreduction of N2 to NH3. We demonstrate experimentally the significance of various sources of contamination and show how to remove labile nitrogen-containing compounds present in the N2 gas and how to perform quantitative isotope measurements with cycling of 15N2 gas to reduce both contamination and the cost of isotope measurements. Following this protocol, we obtain negative results when using the most promising pure metal catalysts in aqueous media, and successfully confirm and quantify ammonia synthesis using lithium electrodeposition in tetrahydrofuran13.

    View details for DOI 10.1038/s41586-019-1260-x

    View details for PubMedID 31117118

  • Progress and Perspectives of Electrochemical CO2 Reduction on Copper in Aqueous Electrolyte. Chemical reviews Nitopi, S., Bertheussen, E., Scott, S. B., Liu, X., Engstfeld, A. K., Horch, S., Seger, B., Stephens, I. E., Chan, K., Hahn, C., Norskov, J. K., Jaramillo, T. F., Chorkendorff, I. 2019

    Abstract

    To date, copper is the only heterogeneous catalyst that has shown a propensity to produce valuable hydrocarbons and alcohols, such as ethylene and ethanol, from electrochemical CO2 reduction (CO2R). There are variety of factors that impact CO2R activity and selectivity, including the catalyst surface structure, morphology, composition, the choice of electrolyte ions and pH, and the electrochemical cell design. Many of these factors are often intertwined, which can complicate catalyst discovery and design efforts. Here we take a broad and historical view of these different aspects and their complex interplay in CO2R catalysis on Cu, with the purpose of providing new insights, critical evaluations, and guidance to the field with regard to research directions and best practices. First, we describe the various experimental probes and complementary theoretical methods that have been used to discern the mechanisms by which products are formed, and next we present our current understanding of the complex reaction networks for CO2R on Cu. We then analyze two key methods that have been used in attempts to alter the activity and selectivity of Cu: nanostructuring and the formation of bimetallic electrodes. Finally, we offer some perspectives on the future outlook for electrochemical CO2R.

    View details for DOI 10.1021/acs.chemrev.8b00705

    View details for PubMedID 31117420

  • Transition Metal-Modified Exfoliated Zirconium Phosphate as an Electrocatalyst for the Oxygen Evolution Reaction ACS APPLIED ENERGY MATERIALS Ramos-Garces, M. V., Sanchez, J., Del Toro-Pedrosa, D. E., Alvarez, I., Yu, Y., Valle, E., Villagran, D., Jaramillo, T. F., Colon, J. L. 2019; 2 (5): 3561–67
  • Influence of Atomic Surface Structure on the Activity of Ag for the Electrochemical Reduction of CO2 to CO ACS CATALYSIS Clark, E. L., Ringe, S., Tang, M., Walton, A., Hahn, C., Jaramillo, T. F., Chan, K., Bell, A. T. 2019; 9 (5): 4006–14
  • What would it take for renewably powered electrosynthesis to displace petrochemical processes? SCIENCE De Luna, P., Hahn, C., Higgins, D., Jaffer, S. A., Jaramillo, T. F., Sargent, E. H. 2019; 364 (6438): 350-+
  • Robust and biocompatible catalysts for efficient hydrogen-driven microbial electrosynthesis COMMUNICATIONS CHEMISTRY Kracke, F., Wong, A., Maegaard, K., Deutzmann, J. S., Hubert, M. A., Hahn, C., Jaramillo, T. F., Spormann, A. M. 2019; 2
  • Development of Molybdenum Phosphide Catalysts for Higher Alcohol Synthesis from Syngas by Exploiting Support and Promoter Effects ENERGY TECHNOLOGY ten Have, I. C., Valle, E., Gallo, A., Snider, J. L., Duyar, M. S., Jaramillo, T. F. 2019; 7 (5)
  • Revealing the Synergy between Oxide and Alloy Phases on the Performance of Bimetallic In-Pd Catalysts for CO2 Hydrogenation to Methanol ACS CATALYSIS Snider, J. L., Streibel, V., Hubert, M. A., Choksi, T. S., Valle, E., Upham, D., Schumann, J., Duyar, M. S., Gallo, A., Abild-Pedersen, F., Jaramillo, T. F. 2019; 9 (4): 3399–3412
  • Quantitative protocol for the electroreduction of N2 to NH3 under ambient conditions Stephens, I., Andersen, S., Colic, V., Yang, S., Schwalbe, J., Nielander, A., McEnaney, J., Enemark-Rasmussen, K., Baker, J., Singh, A., Rohr, B., Blair, S., Mezzavilla, S., Kibsgaard, J., Vesborg, P., Cargnello, M., Bent, S., Jaramillo, T., Norskov, J., Chorkendorff, I. AMER CHEMICAL SOC. 2019
  • Observing hydrogen intercalation into palladium thin films using in situ grazing incidence x-ray diffraction and x-ray reflectivity Landers, A., Feaster, J., Brown, K., Lin, J., Farmand, M., Fackler, S., Nishimura, Y., Beeman, J., Bajdich, M., Higgins, D., Yano, J., Drisdell, W., Davis, R., Hahn, C., Mehta, A., Jaramillo, T. AMER CHEMICAL SOC. 2019
  • Proton control in electrochemical ammonia synthesis Schwalbe, J., Singh, A., Rohr, B., Statt, M., Nielander, A., McEnaney, J., Andersen, S., Colic, V., Yang, S., Chorkendorff, I., Jaramillo, T., Norskov, J., Cargnello, M. AMER CHEMICAL SOC. 2019
  • Absence of Oxidized Phases in Cu under CO Reduction Conditions ACS ENERGY LETTERS Scott, S. B., Hogg, T. V., Landers, A. T., Maagaard, T., Bertheussen, E., Lin, J. C., Davis, R. C., Beeman, J. W., Higgins, D., Drisdell, W. S., Hahn, C., Mehta, A., Seger, B., Jaramillo, T. F., Chorkendorff, I. 2019; 4 (3): 803–4
  • Electrochemical flow cell enabling operando probing of electrocatalyst surfaces by X-ray spectroscopy and diffraction. Physical chemistry chemical physics : PCCP Farmand, M., Landers, A. T., Lin, J. C., Feaster, J. T., Beeman, J. W., Ye, Y., Clark, E. L., Higgins, D., Yano, J., Davis, R. C., Mehta, A., Jaramillo, T. F., Hahn, C., Drisdell, W. S. 2019

    Abstract

    The rational improvement of current and developing electrochemical technologies requires atomistic understanding of electrode-electrolyte interfaces. However, examining these interfaces under operando conditions, where performance is typically evaluated and benchmarked, remains challenging, as it necessitates incorporating an operando probe during full electrochemical operation. In this study, we describe a custom electrochemical flow cell that enables near-surface-sensitive operando investigation of planar thin-film catalysts at significant hydrogen evolution reaction (HER) rates (in excess of -100 mA cm-2) using grazing incidence X-ray methods. Grazing-incidence X-ray spectroscopy and diffraction were implemented on the same sample under identical HER conditions, demonstrating how the combined measurements track changing redox chemistry and structure of Cu thin-film catalyst surfaces as a function of electrochemical conditions. The coupling of these methods with improved mass transport and hydrodynamic control establishes a new paradigm for operando measurement design, enabling unique insights into the key fundamental processes occurring at the catalyst-electrolyte interface.

    View details for DOI 10.1039/c8cp07423b

    View details for PubMedID 30785434

  • Molybdenum Disulfide Catalytic Coatings via Atomic Layer Deposition for Solar Hydrogen Production from Copper Gallium Diselenide Photocathodes ACS APPLIED ENERGY MATERIALS Hellstern, T. R., Palm, D. W., Carter, J., DeAngelis, A. D., Horsley, K., Weinhardt, L., Yang, W., Blum, M., Gaillard, N., Heske, C., Jaramillo, T. F. 2019; 2 (2): 1060–66
  • pH effects on the electrochemical reduction of CO(2) towards C-2 products on stepped copper NATURE COMMUNICATIONS Liu, X., Schlexer, P., Xiao, J., Ji, Y., Wang, L., Sandberg, R. B., Tang, M., Brown, K. S., Peng, H., Ringe, S., Hahn, C., Jaramillo, T. F., Norskov, J. K., Chan, K. 2019; 10
  • pH effects on the electrochemical reduction of CO(2) towards C2 products on stepped copper. Nature communications Liu, X., Schlexer, P., Xiao, J., Ji, Y., Wang, L., Sandberg, R. B., Tang, M., Brown, K. S., Peng, H., Ringe, S., Hahn, C., Jaramillo, T. F., Norskov, J. K., Chan, K. 2019; 10 (1): 32

    Abstract

    We present a microkinetic model for CO(2) reduction (CO(2)R) on Cu(211) towards C2 products, based on energetics estimated from an explicit solvent model. We show that the differences in both Tafel slopes and pH dependence for C1 vs C2 activity arise from differences in their multi-step mechanisms. We find the depletion in C2 products observed at high overpotential and high pH to arise from the 2nd order dependence of C-C coupling on CO coverage, which decreases due to competition from the C1 pathway. We further demonstrate that CO(2) reduction at a fixed pH yield similar activities, due to the facile kinetics for CO2 reduction to CO on Cu, which suggests C2 products to be favored for CO2R under alkaline conditions. The mechanistic insights of this work elucidate how reaction conditions can lead to significant enhancements in selectivity and activity towards higher value C2 products.

    View details for PubMedID 30604776

  • Systematic Investigation of Iridium-Based Bimetallic Thin Film Catalysts for the Oxygen Evolution Reaction in Acidic Media. ACS applied materials & interfaces Strickler, A. L., Flores, R. A., King, L. A., Nørskov, J. K., Bajdich, M., Jaramillo, T. F. 2019

    Abstract

    Multimetallic Ir-based systems offer significant opportunities for enhanced oxygen evolution electrocatalysis by modifying the electronic and geometric properties of the active catalyst. Herein, a systematic investigation of bimetallic Ir-based thin films was performed to identify activity and stability trends across material systems for the oxygen evolution reaction (OER) in acidic media. Electron beam evaporation was used to co-deposit metallic films of Ir, IrSn2, IrCr, IrTi, and IrNi. The electrocatalytic activity of the electrochemically oxidized alloys was found to increase in the following order: IrTi < IrSn2 < Ir ∼ IrNi < IrCr. The IrCr system demonstrates two times the catalytic activity of Ir at 1.65 V versus RHE. Density functional theory calculations suggest that this enhancement is due to Cr active sites that have improved oxygen binding energetics compared to those of pure Ir oxide. This work identifies IrCr as a promising new catalyst system that facilitates reduced precious metal loadings for acid-based OER catalysis.

    View details for DOI 10.1021/acsami.9b13697

    View details for PubMedID 31442022

  • Author Correction: A rigorous electrochemical ammonia synthesis protocol with quantitative isotope measurements. Nature Andersen, S. Z., Čolić, V., Yang, S., Schwalbe, J. A., Nielander, A. C., McEnaney, J. M., Enemark-Rasmussen, K., Baker, J. G., Singh, A. R., Rohr, B. A., Statt, M. J., Blair, S. J., Mezzavilla, S., Kibsgaard, J., Vesborg, P. C., Cargnello, M., Bent, S. F., Jaramillo, T. F., Stephens, I. E., Nørskov, J. K., Chorkendorff, I. 2019

    Abstract

    An Amendment to this paper has been published and can be accessed via a link at the top of the paper.

    View details for DOI 10.1038/s41586-019-1625-1

    View details for PubMedID 31554972

  • What would it take for renewably powered electrosynthesis to displace petrochemical processes? Science (New York, N.Y.) De Luna, P., Hahn, C., Higgins, D., Jaffer, S. A., Jaramillo, T. F., Sargent, E. H. 2019; 364 (6438)

    Abstract

    Electrocatalytic transformation of carbon dioxide (CO2) and water into chemical feedstocks offers the potential to reduce carbon emissions by shifting the chemical industry away from fossil fuel dependence. We provide a technoeconomic and carbon emission analysis of possible products, offering targets that would need to be met for economically compelling industrial implementation to be achieved. We also provide a comparison of the projected costs and CO2 emissions across electrocatalytic, biocatalytic, and fossil fuel-derived production of chemical feedstocks. We find that for electrosynthesis to become competitive with fossil fuel-derived feedstocks, electrical-to-chemical conversion efficiencies need to reach at least 60%, and renewable electricity prices need to fall below 4 cents per kilowatt-hour. We discuss the possibility of combining electro- and biocatalytic processes, using sequential upgrading of CO2 as a representative case. We describe the technical challenges and economic barriers to marketable electrosynthesized chemicals.

    View details for PubMedID 31023896

  • Nanostructuring Strategies To Increase the Photoelectrochemical Water Splitting Activity of Silicon Photocathodes ACS APPLIED NANO MATERIALS Hellstern, T. R., Nielander, A. C., Chakthranont, P., King, L. A., Willis, J. J., Xu, S., MacIsaac, C., Hahn, C., Bent, S. F., Prinz, F. B., Jaramillo, T. F. 2019; 2 (1): 6–11
  • Gas-Diffusion Electrodes for Carbon Dioxide Reduction: A New Paradigm ACS ENERGY LETTERS Higgins, D., Hahn, C., Xiang, C., Jaramillo, T. F., Weber, A. Z. 2019; 4 (1): 317–24
  • Guiding Electrochemical Carbon Dioxide Reduction toward Carbonyls Using Copper Silver Thin Films with Interphase Miscibility ACS ENERGY LETTERS Higgins, D., Landersp, A. T., Ji, Y., Nitopi, S., Morales-Guio, C. G., Wang, L., Chan, K., Hahn, C., Jaramillo, T. F. 2018; 3 (12): 2947–55
  • A Highly Active Molybdenum Phosphide Catalyst for Methanol Synthesis from CO and CO2 ANGEWANDTE CHEMIE-INTERNATIONAL EDITION Duyar, M. S., Tsai, C., Snider, J. L., Singh, J. A., Gallo, A., Yoo, J., Medford, A. J., Abild-Pedersen, F., Studt, F., Kibsgaard, J., Bent, S. F., Norskov, J. K., Jaramillo, T. F. 2018; 57 (46): 15045–50

    Abstract

    Methanol is a major fuel and chemical feedstock currently produced from syngas, a CO/CO2 /H2 mixture. Herein we identify formate binding strength as a key parameter limiting the activity and stability of known catalysts for methanol synthesis in the presence of CO2 . We present a molybdenum phosphide catalyst for CO and CO2 reduction to methanol, which through a weaker interaction with formate, can improve the activity and stability of methanol synthesis catalysts in a wide range of CO/CO2 /H2 feeds.

    View details for PubMedID 30134041

  • Improved CO2 reduction activity towards C2+ alcohols on a tandem gold on copper electrocatalyst NATURE CATALYSIS Morales-Guio, C. G., Cave, E. R., Nitopi, S. A., Feaster, J. T., Wang, L., Kuhl, K. P., Jackson, A., Johnson, N. C., Abram, D. N., Hatsukade, T., Hahn, C., Jaramillo, T. F. 2018; 1 (10): 764–71
  • Water splitting electrocatalysis within zirconium phosphate layered inorganic nanomaterials Colon, J., Ramos-Garces, M., Sanchez, J., Barraza, I., Wu, Y., Del Toro, D., Villagran, D., Jaramillo, T. AMER CHEMICAL SOC. 2018
  • Metal-modified zirconium phosphate monolayers for the oxygen evolution reaction Ramos-Garces, M., Sanchez, J., Jaramillo, T., Colon, J. AMER CHEMICAL SOC. 2018
  • Intercalation of rhenium bipyridine complexes with zirconium phosphate nanoparticles for energy-related reactions Del Toro-Pedrosa, D., Ramos-Garces, M., Colon, J., Jaramillo, T., Perez, J., Riera, L., Fombona, S., Arevalo, R. AMER CHEMICAL SOC. 2018
  • Quasi-2D Pd/Pt nanoclams for CO2 reduction in tandem with microbial communities Wong, A., Kracke, F., Antoniuk-Pablant, A., Hahn, C., Spormann, A., Jaramillo, T. AMER CHEMICAL SOC. 2018
  • Electrochemical Carbon Monoxide Reduction on Polycrystalline Copper: Effects of Potential, Pressure, and pH on Selectivity toward Multicarbon and Oxygenated Products ACS CATALYSIS Wang, L., Nitopi, S. A., Bertheussen, E., Orazov, M., Morales-Guio, C. G., Liu, X., Higgins, D. C., Chan, K., Norskov, J. K., Hahn, C., Jaramillo, T. F. 2018; 8 (8): 7445–54
  • Extending the limits of Pt/C catalysts with passivation-gas-incorporated atomic layer deposition NATURE CATALYSIS Xu, S., Kim, Y., Park, J., Higgins, D., Shen, S., Schindler, P., Thian, D., Provine, J., Torgersen, J., Graf, T., Schladt, T. D., Orazov, M., Liu, B., Jaramillo, T. F., Prinz, F. B. 2018; 1 (8): 624–30
  • Rapid flame doping of Co to WS2 for efficient hydrogen evolution ENERGY & ENVIRONMENTAL SCIENCE Shi, X., Fields, M., Park, J., McEnaney, J. M., Yan, H., Zhang, Y., Tsai, C., Jaramillo, T. F., Sinclair, R., Norskov, J. K., Zheng, X. 2018; 11 (8): 2270–77

    View details for DOI 10.1039/c8ee01111g

    View details for Web of Science ID 000442262900035

  • A Universal Platform for Fabricating Organic Electrochemical Devices ADVANCED ELECTRONIC MATERIALS Duong, D. T., Tuchman, Y., Chakthranont, P., Cavassin, P., Colucci, R., Jaramillo, T. F., Salleo, A., Faria, G. C. 2018; 4 (7)
  • Standards and Protocols for Data Acquisition and Reporting for Studies of the Electrochemical Reduction of Carbon Dioxide ACS CATALYSIS Clark, E. L., Resasco, J., Landers, A., Lin, J., Chung, L., Walton, A., Hahn, C., Jaramillo, T. F., Bell, A. T. 2018; 8 (7): 6560–70
  • Designing Boron Nitride Islands in Carbon Materials for Efficient Electrochemical Synthesis of Hydrogen Peroxide. Journal of the American Chemical Society Chen, S., Chen, Z., Siahrostami, S., Higgins, D., Nordlund, D., Sokaras, D., Kim, T. R., Liu, Y., Yan, X., Nilsson, E., Sinclair, R., Norskov, J. K., Jaramillo, T. F., Bao, Z. 2018; 140 (25): 7851–59

    Abstract

    Heteroatom-doped carbons have drawn increasing research interest as catalysts for various electrochemical reactions due to their unique electronic and surface structures. In particular, co-doping of carbon with boron and nitrogen has been shown to provide significant catalytic activity for oxygen reduction reaction (ORR). However, limited experimental work has been done to systematically study these materials, and much remains to be understood about the nature of the active site(s), particularly with regards to the factors underlying the activity enhancements of these boron-carbon-nitrogen (BCN) materials. Herein, we prepare several BCN materials experimentally with a facile and controlled synthesis method, and systematically study their electrochemical performance. We demonstrate the existence of h-BN domains embedded in the graphitic structures of these materials using X-ray spectroscopy. These synthesized structures yield higher activity and selectivity toward the 2e- ORR to H2O2 than structures with individual B or N doping. We further employ density functional theory calculations to understand the role of a variety of h-BN domains within the carbon lattice for the ORR and find that the interface between h-BN domains and graphene exhibits unique catalytic behavior that can preferentially drive the production of H2O2. To the best of our knowledge, this is the first example of h-BN domains in carbon identified as a novel system for the electrochemical production of H2O2.

    View details for PubMedID 29874062

  • The Predominance of Hydrogen Evolution on Transition Metal Sulfides and Phosphides under CO2 Reduction Conditions: An Experimental and Theoretical Study ACS ENERGY LETTERS Landers, A. T., Fields, M., Torelli, D. A., Xiao, J., Hellstern, T. R., Francis, S. A., Tsai, C., Kibsgaard, J., Lewis, N. S., Chan, K., Hahn, C., Jaramillo, T. F. 2018; 3 (6): 1450–57
  • Cyclic-Voltammetry-Based Solid-State Gas Sensor for Methane and Other VOC Detection ANALYTICAL CHEMISTRY Gross, P., Jaramillo, T., Pruitt, B. 2018; 90 (10): 6102–8

    Abstract

    We present the fabrication, characterization, and testing of an electrochemical volatile organic compound (VOC) sensor operating in gaseous conditions at room temperature. It is designed to be microfabricated and to prove the sensing principle based on cyclic voltammetry (CV). It is composed of a working electrode (WE), a counter electrode (CE), a reference electrode (RE), and a Nafion solid-state electrolyte. Nafion is a polymer that conducts protons (H+) generated from redox reactions from the WE to the CE. The sensor needs to be activated prior to exposure to gases, which consists of hydrating the Nafion layer to enable its ion conduction properties. During testing, we have shown that our sensor is not only capable of detecting methane, but it can also quantify its concentration in the gas flow as well as differentiate its signal from carbon monoxide (CO). These results have been confirmed by exposing the sensor to two different concentrations of methane (50% and 10% of methane diluted in N2), as well as pure CO. Although the signal is positioned in the Hads region of Pt, because of thermodynamic reasons it cannot be directly attributed to methane oxidation into CO2. However, its consistency suggests the presence of a methane-related oxidation process that can be used for detection, identification, and quantification purposes.

    View details for DOI 10.1021/acs.analchem.8b00184

    View details for Web of Science ID 000432478600020

    View details for PubMedID 29644861

  • Copper Silver Thin Films with Metastable Miscibility for Oxygen Reduction Electrocatalysis in Alkaline Electrolytes ACS APPLIED ENERGY MATERIALS Higgins, D., Wette, M., Gibbons, B. M., Siahrostami, S., Hahn, C., Escudero-Escribano, M., Garcia-Melchor, M., Ulissi, Z., Davis, R. C., Mehta, A., Clemens, B. M., Norskov, J. K., Jaramillo, T. F. 2018; 1 (5): 1990–99
  • Trends in the Catalytic Activity of Hydrogen Evolution during CO2 Electroreduction on Transition Metals ACS CATALYSIS Cave, E. R., Shi, C., Kuhl, K. P., Hatsukade, T., Abram, D. N., Hahn, C., Chan, K., Jaramillo, T. F. 2018; 8 (4): 3035–40
  • Uniform Pt/Pd bimetallic nanocrystals demonstrate platinum effect on palladium methane combustion activity and stability Goodman, E., Dai, S., Yang, A., Wrasman, C., Gallo, A., Bare, S., Hoffman, A., Jaramillo, T., Graham, G., Pan, X., Cargnello, M. AMER CHEMICAL SOC. 2018
  • Electrochemical reduction of carbon dioxide over bimetallic metal-on-copper electrocatalysts Nishimura, Y., Hahn, C., Jaramillo, T. AMER CHEMICAL SOC. 2018
  • Nanoparticles via vapor phase condensation for energy applications Clemens, B., Gibbons, B., Wetter, M., Higgins, D., Jaramillo, T., Baker, J., Bent, S., Mehta, A., Davis, R. AMER CHEMICAL SOC. 2018
  • Electrochemical cycling strategy for selective and sustainable C2H2 production from CO2 or CH4 at atmospheric pressure using H2O McEnaney, J., Rohr, B., Nielander, A., Singh, A., Norskov, J., Jaramillo, T. AMER CHEMICAL SOC. 2018
  • alpha-Zirconium phosphate frameworks as supports for active oxygen evolution reaction electrocatalysts Ramos-Garces, M., Sanchez, J., Jaramillo, T., Colon, J. AMER CHEMICAL SOC. 2018
  • High-efficiency oxygen reduction to hydrogen peroxide catalysed by oxidized carbon materials NATURE CATALYSIS Lu, Z., Chen, G., Siahrostami, S., Chen, Z., Liu, K., Xie, J., Liao, L., Wu, T., Lin, D., Liu, Y., Jaramillo, T. F., Norskov, J. K., Cui, Y. 2018; 1 (2): 156–62
  • Engineering Ru@Pt Core-Shell Catalysts for Enhanced Electrochemical Oxygen Reduction Mass Activity and Stability. Nanomaterials (Basel, Switzerland) Jackson, A., Strickler, A., Higgins, D., Jaramillo, T. F. 2018; 8 (1)

    Abstract

    Improving the performance of oxygen reduction reaction (ORR) electrocatalysts is essential for the commercial efficacy of many renewable energy technologies, including low temperature polymer electrolyte fuel cells (PEFCs). Herein, we report highly active and stable carbon-supported Ru@Pt core-shell nanoparticles (Ru@Pt/C) prepared by a wet chemical synthesis technique. Through rotating disc electrode testing, the Ru@Pt/C achieves an ORR Pt mass-based activity of 0.50 A mgPt-1 at 0.9 V versus the reversible hydrogen electrode (RHE), which exceeds the activity of the state-of-the-art commercial Pt/C catalyst as well as the Department of Energy 2020 PEFC electrocatalyst activity targets for transportation applications. The impact of various synthetic parameters, including Pt to Ru ratios and catalyst pretreatments (i.e., annealing) are thoroughly explored. Pt-based mass activity of all prepared Ru@Pt/C catalysts was found to exceed 0.4 mgPt-1 across the range of compositions investigated, with the maximum activity catalyst having a Ru:Pt ratio of 1:1. This optimized composition of Ru@Pt/C catalyst demonstrated remarkable stability after 30,000 accelerated durability cycles (0.6 to 1.0 V vs. RHE at 125 mV s-1), maintaining 85% of its initial mass activity. Scanning transmission electron microscopy energy dispersive spectroscopy (STEM-EDS) analysis at various stages of electrochemical testing demonstrated that the Pt shell can provide sufficient protection against the dissolution of the otherwise unstable Ru core.

    View details for PubMedID 29329264

  • Defective Carbon-Based Materials for the Electrochemical Synthesis of Hydrogen Peroxide ACS SUSTAINABLE CHEMISTRY & ENGINEERING Chen, S., Chen, Z., Siahrostami, S., Kim, T., Nordlund, D., Sokaras, D., Nowak, S., To, J. F., Higgins, D., Sinclair, R., Norskov, J. K., Jaramillo, T. F., Bao, Z. 2018; 6 (1): 311–17
  • Impact of Nanostructuring on the Photoelectrochemical Performance of Si/Ta3N5 Nanowire Photoanodes JOURNAL OF PHYSICAL CHEMISTRY C Narkeviciute, I., Jaramillo, T. F. 2017; 121 (49): 27295–302
  • Design and Fabrication of a Precious Metal-Free Tandem Core-Shell p(+)n Si/W-Doped BiVO4 Photoanode for Unassisted Water Splitting ADVANCED ENERGY MATERIALS Chakthranont, P., Hellstern, T. R., McEnaney, J. M., Jaramillo, T. F. 2017; 7 (22)
  • Electrochemical CO2 Reduction over Compressively Strained CuAg Surface Alloys with Enhanced Multi-Carbon Oxygenate Selectivity JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Clark, E. L., Hahn, C., Jaramillo, T. F., Bell, A. T. 2017; 139 (44): 15848–57

    Abstract

    The electrochemical reduction of carbon dioxide using renewably generated electricity offers a potential means for producing fuels and chemicals in a sustainable manner. To date, copper has been found to be the most effective catalyst for electrochemically reducing carbon dioxide to products such as methane, ethene, and ethanol. Unfortunately, the current efficiency of the process is limited by competition with the relatively facile hydrogen evolution reaction. Since multi-carbon products are more valuable precursors to chemicals and fuels than methane, there is considerable interest in modifying copper to enhance the multi-carbon product selectivity. Here, we report our investigations of electrochemical carbon dioxide reduction over CuAg bimetallic electrodes and surface alloys, which we find to be more selective for the formation of multi-carbon products than pure copper. This selectivity enhancement is a result of the selective suppression of hydrogen evolution, which occurs due to compressive strain induced by the formation of a CuAg surface alloy. Furthermore, we report that these bimetallic electrocatalysts exhibit an unusually high selectivity for the formation of multi-carbon carbonyl-containing products, which we hypothesize to be the consequence of a reduced coverage of adsorbed hydrogen and the reduced oxophilicity of the compressively strained copper. Thus, we show that promoting copper surface with small amounts of Ag is a promising means for improving the multi-carbon oxygenated product selectivity of copper during electrochemical CO2 reduction.

    View details for PubMedID 28988474

  • Effects of Ta3N5 Morphology and Composition on the Performance of Si-Ta3N5 Photoanodes SOLAR RRL Narkeviciute, I., Jaramillo, T. F. 2017; 1 (11)
  • Systematic Structure Property Relationship Studies in Palladium Catalyzed Methane Complete Combustion ACS CATALYSIS Willis, J. J., Gallo, A., Sokaras, D., Aljama, H., Nowak, S. H., Goodman, E. D., Wu, L., Tassone, C. J., Jaramillo, T. F., Abild-Pedersen, F., Cargnello, M. 2017; 7 (11): 7810–21
  • Highly Stable Molybdenum Disulfide Protected Silicon Photocathodes for Photoelectrochemical Water Splitting ACS APPLIED MATERIALS & INTERFACES King, L. A., Hellstern, T. R., Park, J., Sinclair, R., Jaramillo, T. F. 2017; 9 (42): 36792–98

    Abstract

    Developing materials, interfaces, and devices with improved stability remains one of the key challenges in the field of photoelectrochemical water splitting. As a barrier to corrosion, molybdenum disulfide is a particularly attractive protection layer for photocathodes due to its inherent stability in acid, the low permeability of its basal planes, and the excellent hydrogen evolution reaction (HER) activity the MoS2 edge. Here, we demonstrate a stable silicon photocathode containing a protecting layer consisting of molybdenum disulfide, molybdenum silicide, and silicon oxide which operates continuously for two months. We make comparisons between this system and another molybdenum sulfide-silicon photocathode embodiment, taking both systems to catastrophic failure during photoelectrochemical stability measurements and exploring mechanisms of degradation. X-ray photoelectron spectroscopy and transmission electron microscopy provide key insights into the origins of stability.

    View details for PubMedID 29035498

  • Mesoporous Ruthenium/Ruthenium Oxide Thin Films: Active Electrocatalysts for the Oxygen Evolution Reaction CHEMELECTROCHEM Kibsgaard, J., Hellstern, T. R., Choi, S., Reinecke, B. N., Jaramillo, T. F. 2017; 4 (10): 2480–85
  • Core-Shell Au@Metal-Oxide Nanoparticle Electrocatalysts for Enhanced Oxygen Evolution NANO LETTERS Strickler, A. L., Escudero-Escribano, M., Jaramillo, T. F. 2017; 17 (10): 6040–46

    Abstract

    Enhanced catalysis for electrochemical oxygen evolution is essential for the efficacy of many renewable energy technologies, including water electrolyzers and metal-air batteries. Recently, Au supports have been shown to enhance the activity of many 3d transition metal-oxide thin films for the oxygen evolution reaction (OER) in alkaline media. Herein, we translate the beneficial impact of Au supports to high surface area, device-ready core-shell nanoparticles consisting of a Au-core and a metal-oxide shell (Au@MxOy where M = Ni, Co, Fe, and CoFe). Through a systematic evaluation, we establish trends in performance and illustrate the universal activity enhancement when employing the Au-core in the 3d transition metal-oxide nanoparticles. The highest activity particles, Au@CoFeOx, demonstrate an overpotential of 328 ± 3 mV over a 2 h stability test at 10 mA cm-2, illustrating that strategically coupling Au support and mixed metal-oxide effects in a core-shell nanoparticle morphology is a promising avenue to achieve device-ready, high-performance OER catalysts.

    View details for PubMedID 28945433

  • Machine-Learning Methods Enable Exhaustive Searches for Active Bimetallic Facets and Reveal Active Site Motifs for CO2 Reduction ACS CATALYSIS Ulissi, Z. W., Tang, M. T., Xiao, J., Liu, X., Torelli, D. A., Karamad, M., Cummins, K., Hahn, C., Lewis, N. S., Jaramillo, T. F., Chan, K., Norskov, J. K. 2017; 7 (10): 6600–6608
  • Investigating Catalyst-Support Interactions To Improve the Hydrogen Evolution Reaction Activity of Thiomolybdate [Mo3S13](2-) Nanoclusters ACS CATALYSIS Hellstern, T. R., Kibsgaard, J., Tsai, C., Palm, D. W., King, L. A., Abild-Pedersen, F., Jaramillo, T. F. 2017; 7 (10): 7126–30
  • Understanding activity trends in electrochemical water oxidation to form hydrogen peroxide NATURE COMMUNICATIONS Shi, X., Siahrostami, S., Li, G., Zhang, Y., Chakthranont, P., Studt, F., Jaramillo, T. F., Zheng, X., Norskov, J. K. 2017; 8: 701

    Abstract

    Electrochemical production of hydrogen peroxide (H2O2) from water oxidation could provide a very attractive route to locally produce a chemically valuable product from an abundant resource. Herein using density functional theory calculations, we predict trends in activity for water oxidation towards H2O2 evolution on four different metal oxides, i.e., WO3, SnO2, TiO2 and BiVO4. The density functional theory predicted trend for H2O2 evolution is further confirmed by our experimental measurements. Moreover, we identify that BiVO4 has the best H2O2 generation amount of those oxides and can achieve a Faraday efficiency of about 98% for H2O2 production.Producing hydrogen peroxide via electrochemical oxidation of water is an attractive route to this valuable product. Here the authors theoretically and experimentally investigate hydrogen peroxide production activity trends for a range of metal oxides and identify the optimal bias ranges for high Faraday efficiencies.

    View details for PubMedID 28951571

  • Understanding the Influence of [EMIM]CI on the Suppression of the Hydrogen Evolution Reaction on Transition Metal Electrodes LANGMUIR Feaster, J. T., Jongerius, A. L., Liu, X., Urushihara, M., Nitopi, S. A., Hahn, C., Chan, K., Norskov, J. K., Jaramillo, T. F. 2017; 33 (37): 9464–71

    Abstract

    We have studied the influence of low concentrations (0.1 M) of the ionic liquid 1-ethyl-3-methylimidazolium chloride ([EMIM]Cl) on suppressing the hydrogen evolution reaction (HER) using polycrystalline Ag, Cu, and Fe electrodes in aqueous acidic and basic media. HER suppression is generally desired when aiming to catalyze other reactions of interests, e.g., CO2 electro-reduction. Cyclic voltammetry and chronoamperometry measurements were performed at potentials between -0.2 and -0.8 V versus the reversible hydrogen electrode (RHE) to investigate HER activity in a simulated CO2 electrolysis environment without the CO2. In an acidic electrolyte, a decrease in HER activity was observed for all three electrodes with the largest effect being that of Fe, where the HER activity was suppressed by 75% at -0.5 V versus RHE. In contrast to the effect of [EMIM]Cl in an acidic electrolyte, no HER suppression was observed in basic media. Using 1H nuclear magnetic resonance spectroscopy on the electrolyte before and after electrolysis, it was determined that [EMIM]Cl breaks down at both the working and counter electrodes under reaction conditions under both acidic and basic conditions. These results underscore the challenges in employing ionic liquids for electrochemical reactions such as CO2 reduction.

    View details for PubMedID 28691827

  • Polyol Synthesis of Cobalt-Copper Alloy Catalysts for Higher Alcohol Synthesis from Syngas CATALYSIS LETTERS Mendes, L. P., Snider, J. L., Fleischman, S. D., Kibsgaard, J., McEnaney, J. M., Aranda, D. G., Jaramillo, T. F. 2017; 147 (9): 2352–59
  • Multimodal x-ray characterization of solar fuels catalysts under operation Farmand, M., Feaster, J., Davis, R., Fackler, S., Landers, A., Lin, J., Hahn, C., Jaramillo, T., Yano, J., Mehta, A., Drisdell, W. AMER CHEMICAL SOC. 2017
  • Water oxidation electrocatalysis by transition metals supported onto zirconium phosphate nanoparticles Ramos-Garces, M., Sanchez, J., Narkeviciute, I., Jaramillo, T., Colon, J. AMER CHEMICAL SOC. 2017
  • High-yield ammonia synthesis via an electrochemical cycling process using N2 and H2O at atmospheric pressure McEnaney, J., Singh, A., Schwalbe, J., Kibsgaard, J., Lin, J., Cargnello, M., Jaramillo, T., Norskov, J. AMER CHEMICAL SOC. 2017
  • Promoter Effects of Alkali Metal Cations on the Electrochemical Reduction of Carbon Dioxide JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Resasco, J., Chen, L. D., Clark, E., Tsai, C., Hahn, C., Jaramillo, T. F., Chan, K., Bell, A. T. 2017; 139 (32): 11277–87

    Abstract

    The electrochemical reduction of CO2 is known to be influenced by the identity of the alkali metal cation in the electrolyte; however, a satisfactory explanation for this phenomenon has not been developed. Here we present the results of experimental and theoretical studies aimed at elucidating the effects of electrolyte cation size on the intrinsic activity and selectivity of metal catalysts for the reduction of CO2. Experiments were conducted under conditions where the influence of electrolyte polarization is minimal in order to show that cation size affects the intrinsic rates of formation of certain reaction products, most notably for HCOO-, C2H4, and C2H5OH over Cu(100)- and Cu(111)-oriented thin films, and for CO and HCOO- over polycrystalline Ag and Sn. Interpretation of the findings for CO2 reduction was informed by studies of the reduction of glyoxal and CO, key intermediates along the reaction pathway to final products. Density functional theory calculations show that the alkali metal cations influence the distribution of products formed as a consequence of electrostatic interactions between solvated cations present at the outer Helmholtz plane and adsorbed species having large dipole moments. The observed trends in activity with cation size are attributed to an increase in the concentration of cations at the outer Helmholtz plane with increasing cation size.

    View details for PubMedID 28738673

  • Effects of Gold Substrates on the Intrinsic and Extrinsic Activity of High-Loading Nickel-Based Oxyhydroxide Oxygen Evolution Catalysts ACS CATALYSIS Chakthranont, P., Kibsgaard, J., Gallo, A., Park, J., Mitani, M., Sokaras, D., Kroll, T., Sinclair, R., Mogensen, M. B., Jaramillo, T. F. 2017; 7 (8): 5399–5409
  • Ammonia synthesis from N-2 and H2O using a lithium cycling electrification strategy at atmospheric pressure ENERGY & ENVIRONMENTAL SCIENCE McEnaney, J. M., Singh, A. R., Schwalbe, J. A., Kibsgaard, J., Lin, J. C., Cargnello, M., Jaramillo, T. F., Norskov, J. K. 2017; 10 (7): 1621–30

    View details for DOI 10.1039/c7ee01126a

    View details for Web of Science ID 000405279900010

  • Understanding Selectivity for the Electrochemical Reduction of Carbon Dioxide to Formic Acid and Carbon Monoxide on Metal Electrodes ACS CATALYSIS Feaster, J. T., Shi, C., Cave, E. R., Hatsukade, T. T., Abram, D. N., Kuhl, K. P., Hahn, C., Norskov, J. K., Jaramillo, T. F. 2017; 7 (7): 4822–27
  • reduction on Au surfaces: mechanistic aspects regarding the formation of major and minor products. Physical chemistry chemical physics : PCCP Cave, E. R., Montoya, J. H., Kuhl, K. P., Abram, D. N., Hatsukade, T., Shi, C., Hahn, C., Nørskov, J. K., Jaramillo, T. F. 2017

    Abstract

    In the future, industrial CO2 electroreduction using renewable energy sources could be a sustainable means to convert CO2 and water into commodity chemicals at room temperature and atmospheric pressure. This study focuses on the electrocatalytic reduction of CO2 on polycrystalline Au surfaces, which have high activity and selectivity for CO evolution. We explore the catalytic behavior of polycrystalline Au surfaces by coupling potentiostatic CO2 electrolysis experiments in an aqueous bicarbonate solution with high sensitivity product detection methods. We observed the production of methanol, in addition to detecting the known products of CO2 electroreduction on Au: CO, H2 and formate. We suggest a mechanism that explains Au's evolution of methanol. Specifically, the Au surface does not favor C-O scission, and thus is more selective towards methanol than methane. These insights could aid in the design of electrocatalysts that are selective for CO2 electroreduction to oxygenates over hydrocarbons.

    View details for DOI 10.1039/c7cp02855e

    View details for PubMedID 28585950

  • : Controlling selectivity toward oxygenates and hydrocarbons. Proceedings of the National Academy of Sciences of the United States of America Hahn, C., Hatsukade, T., Kim, Y., Vailionis, A., Baricuatro, J. H., Higgins, D. C., Nitopi, S. A., Soriaga, M. P., Jaramillo, T. F. 2017; 114 (23): 5918-5923

    Abstract

    In this study we control the surface structure of Cu thin-film catalysts to probe the relationship between active sites and catalytic activity for the electroreduction of CO2 to fuels and chemicals. Here, we report physical vapor deposition of Cu thin films on large-format (∼6 cm(2)) single-crystal substrates, and confirm epitaxial growth in the <100>, <111>, and <751> orientations using X-ray pole figures. To understand the relationship between the bulk and surface structures, in situ electrochemical scanning tunneling microscopy was conducted on Cu(100), (111), and (751) thin films. The studies revealed that Cu(100) and (111) have surface adlattices that are identical to the bulk structure, and that Cu(751) has a heterogeneous kinked surface with (110) terraces that is closely related to the bulk structure. Electrochemical CO2 reduction testing showed that whereas both Cu(100) and (751) thin films are more active and selective for C-C coupling than Cu(111), Cu(751) is the most selective for >2e(-) oxygenate formation at low overpotentials. Our results demonstrate that epitaxy can be used to grow single-crystal analogous materials as large-format electrodes that provide insights on controlling electrocatalytic activity and selectivity for this reaction.

    View details for DOI 10.1073/pnas.1618935114

    View details for PubMedID 28533377

  • Carbon Dioxide Electroreduction using a Silver-Zinc Alloy ENERGY TECHNOLOGY Hatsukade, T., Kuhl, K. P., Cave, E. R., Abram, D. N., Feaster, J. T., Jongerius, A. L., Hahn, C., Jaramillo, T. F. 2017; 5 (6): 955–61
  • Transition Metal-Modified Zirconium Phosphate Electrocatalysts for the Oxygen Evolution Reaction CATALYSTS Sanchez, J., Ramos-Garces, M. V., Narkeviciute, I., Colon, J. L., Jaramillo, T. F. 2017; 7 (5)
  • Nanostructured non-precious metal silicon photocathodes for solar water splitting Hellstern, T., Chakthranont, P., King, L., Narkeviciute, I., Britto, R., Palm, D., Hahn, C., Jaramillo, T. AMER CHEMICAL SOC. 2017
  • Operando electrochemical grazing incidence x-ray absorption and diffraction for the CO2 reduction reaction Feaster, J., Farmand, M., Lin, J., Landers, A., Fackler, S., Davis, R., Mehta, A., Yano, J., Jaramillo, T., Drisdell, W. AMER CHEMICAL SOC. 2017
  • Nanostructured tandem Si-Ta3N5 photoanodes for solar water splitting Narkeviciute, I., Chakthranont, P., Mackus, A., Hahn, C., Pinaud, B., Bent, S., Jaramillo, T. AMER CHEMICAL SOC. 2017
  • Molybdenum disulfide as a protection layer and catalyst for gallium indium phosphide solar water splitting photocathodes Britto, R., Young, J., LaFehr, D., Benck, J., Hahn, C., Deutsch, T., Jaramillo, T. AMER CHEMICAL SOC. 2017
  • Cobalt-copper nanoparticle catalysts for higher alcohols synthesis prepared by water-in-oil microemulsion Snider, J., Jaramillo, T. AMER CHEMICAL SOC. 2017
  • Exploring electrocatalytic N2 activation under mild synthetic conditions Nielander, A., McEnaney, J., Jaramillo, T. AMER CHEMICAL SOC. 2017
  • Developing catalysts and methods for low temperature electrochemical oxidation of methane Boyd, M., Hahn, C., Jaramillo, T. AMER CHEMICAL SOC. 2017
  • Au@MxOy core-shell nanoparticles as catalysts for the oxygen evolution reaction Strickler, A., Escudero-Escribano, M., Jaramillo, T. AMER CHEMICAL SOC. 2017
  • Higher alcohol synthesis via Fischer-Tropsch metal surface modification of MoP catalyst Valle, E., Duyar, M., Jaramillo, T. AMER CHEMICAL SOC. 2017
  • Electrocatalyst design and development for the Oxygen Evolution Reaction (OER) and the electroreduction of CO2 Jaramillo, T. AMER CHEMICAL SOC. 2017
  • Integrated electrochemical-biological systems for the production of fuels and chemicals from CO2 Antoniuk-Pablant, A., Kracke, F., Deutzmann, J., Jaramillo, T., Spormann, A. AMER CHEMICAL SOC. 2017
  • Enhanced electrocatalysis for polymer electrolyte membrane fuel cells and electrolyzers Escudero-Escribano, M., Strickler, A., Jaramillo, T., Stephens, I., Chorkendorff, I. AMER CHEMICAL SOC. 2017
  • Effects of alkylamine electrolyte additives on activity and selectivity in electrochemical carbon dioxide reduction Lin, J., Hahn, C., Jaramillo, T. AMER CHEMICAL SOC. 2017
  • Ionic compounds for electrochemical reduction of carbon dioxide Landers, A., Hellstern, T., Hahn, C., Jaramillo, T. AMER CHEMICAL SOC. 2017
  • Metal modified zirconium hydrogen phosphate for the oxygen evolution reaction Sanchez, J., Ramos, M., Narkeviciute, I., Colon, J., Jaramillo, T. AMER CHEMICAL SOC. 2017
  • Exceptionally stable molybdenum disulfide protection schemes for silicon photocathodes King, L., Hellstern, T., Jaramillo, T. AMER CHEMICAL SOC. 2017
  • Electro-thermochemical cycling process for high-yield ammonia synthesis from N2 and H2O at atmospheric pressure McEnaney, J., Singh, A., Schwalbe, J., Kibsgaard, J., Lin, J., Cargnello, M., Jaramillo, T., Norskov, J. AMER CHEMICAL SOC. 2017
  • Activation and stabilization of copper chalcopyrite light absorbers for photoelectrochemical hydrogen production Palm, D., Hellstern, T., DeAngelis, A., Gaillard, N., Jaramillo, T. AMER CHEMICAL SOC. 2017
  • High-performance oxygen reduction and evolution carbon catalysis: From mechanistic studies to device integration NANO RESEARCH To, J. W., Ng, J. W., Siahrostami, S., Koh, A. L., Lee, Y., Chen, Z., Fong, K. D., Chen, S., He, J., Bae, W., Wilcox, J., Jeong, H. Y., Kim, K., Studt, F., Norskov, J. K., Jaramillo, T. F., Bao, Z. 2017; 10 (4): 1163-1177
  • Development of a reactor with carbon catalysts for modular-scale, low-cost electrochemical generation of H2O2 REACTION CHEMISTRY & ENGINEERING Chen, Z., Chen, S., Siahrostami, S., Chakthranont, P., Hahn, C., Nordlund, D., Dimosthenis, S., Norskov, J. K., Bao, Z., Jaramillo, T. F. 2017; 2 (2): 239–45

    View details for DOI 10.1039/c6re00195e

    View details for Web of Science ID 000403324600016

  • Operando investigation of Au-MnOx thin films with improved activity for the oxygen evolution reaction ELECTROCHIMICA ACTA Frydendal, R., Seitz, L. C., Sokaras, D., Weng, T., Nordlund, D., Chorkendorff, I., Stephens, I. E., Jaramillo, T. F. 2017; 230: 22-28
  • Combining theory and experiment in electrocatalysis: Insights into materials design SCIENCE Seh, Z. W., Kibsgaard, J., Dickens, C. F., Chorkendorff, I. B., Norskov, J. K., Jaramillo, T. F. 2017; 355 (6321): 146-?

    Abstract

    Electrocatalysis plays a central role in clean energy conversion, enabling a number of sustainable processes for future technologies. This review discusses design strategies for state-of-the-art heterogeneous electrocatalysts and associated materials for several different electrochemical transformations involving water, hydrogen, and oxygen, using theory as a means to rationalize catalyst performance. By examining the common principles that govern catalysis for different electrochemical reactions, we describe a systematic framework that clarifies trends in catalyzing these reactions, serving as a guide to new catalyst development while highlighting key gaps that need to be addressed. We conclude by extending this framework to emerging clean energy reactions such as hydrogen peroxide production, carbon dioxide reduction, and nitrogen reduction, where the development of improved catalysts could allow for the sustainable production of a broad range of fuels and chemicals.

    View details for DOI 10.1126/science.aad4998

    View details for Web of Science ID 000391743700032

    View details for PubMedID 28082532

  • Active and Stable Ir@Pt Core-Shell Catalysts for Electrochemical Oxygen Reduction ACS ENERGY LETTERS Strickler, A. L., Jackson, A., Jaramillo, T. F. 2017; 2 (1): 244-249
  • Electrochemical Ammonia Synthesis-The Selectivity Challenge ACS CATALYSIS Singh, A. R., Rohr, B. A., Schwalbe, J. A., Cargnello, M., Chan, K., Jaramillo, T. F., Chorkendorff, I., Norskov, J. K. 2017; 7 (1): 706-709
  • Top-down fabrication of fluorine-doped tin oxide nanopillar substrates for solar water splitting RSC ADVANCES Tang, M. H., Chakthranont, P., Jaramillo, T. F. 2017; 7 (45): 28350–57

    View details for DOI 10.1039/c7ra02937c

    View details for Web of Science ID 000402999300047

  • Materials for solar fuels and chemicals NATURE MATERIALS Montoya, J. H., Seitz, L. C., Chakthranont, P., Vojvodic, A., Jaramillo, T. F., Norskov, J. K. 2017; 16 (1): 70-81

    Abstract

    The conversion of sunlight into fuels and chemicals is an attractive prospect for the storage of renewable energy, and photoelectrocatalytic technologies represent a pathway by which solar fuels might be realized. However, there are numerous scientific challenges in developing these technologies. These include finding suitable materials for the absorption of incident photons, developing more efficient catalysts for both water splitting and the production of fuels, and understanding how interfaces between catalysts, photoabsorbers and electrolytes can be designed to minimize losses and resist degradation. In this Review, we highlight recent milestones in these areas and some key scientific challenges remaining between the current state of the art and a technology that can effectively convert sunlight into fuels and chemicals.

    View details for DOI 10.1038/NMAT4778

    View details for Web of Science ID 000391343300015

  • Materials for solar fuels and chemicals. Nature materials Montoya, J. H., Seitz, L. C., Chakthranont, P., Vojvodic, A., Jaramillo, T. F., Nørskov, J. K. 2016; 16 (1): 70-81

    Abstract

    The conversion of sunlight into fuels and chemicals is an attractive prospect for the storage of renewable energy, and photoelectrocatalytic technologies represent a pathway by which solar fuels might be realized. However, there are numerous scientific challenges in developing these technologies. These include finding suitable materials for the absorption of incident photons, developing more efficient catalysts for both water splitting and the production of fuels, and understanding how interfaces between catalysts, photoabsorbers and electrolytes can be designed to minimize losses and resist degradation. In this Review, we highlight recent milestones in these areas and some key scientific challenges remaining between the current state of the art and a technology that can effectively convert sunlight into fuels and chemicals.

    View details for DOI 10.1038/nmat4778

    View details for PubMedID 27994241

  • Tandem Core-Shell Si-Ta3N5 Photoanodes for Photoelectrochemical Water Splitting NANO LETTERS Narkeviciute, I., Chakthranont, P., Mackus, A. J., Hahn, C., Pinaud, B. A., Bent, S. F., Jaramillo, T. F. 2016; 16 (12): 7565-7572

    Abstract

    Nanostructured core-shell Si-Ta3N5 photoanodes were designed and synthesized to overcome charge transport limitations of Ta3N5 for photoelectrochemical water splitting. The core-shell devices were fabricated by atomic layer deposition of amorphous Ta2O5 onto nanostructured Si and subsequent nitridation to crystalline Ta3N5. Nanostructuring with a thin shell of Ta3N5 results in a 10-fold improvement in photocurrent compared to a planar device of the same thickness. In examining thickness dependence of the Ta3N5 shell from 10 to 70 nm, superior photocurrent and absorbed-photon-to-current efficiencies are obtained from the thinner Ta3N5 shells, indicating minority carrier diffusion lengths on the order of tens of nanometers. The fabrication of a heterostructure based on a semiconducting, n-type Si core produced a tandem photoanode with a photocurrent onset shifted to lower potentials by 200 mV. CoTiOx and NiOx water oxidation cocatalysts were deposited onto the Si-Ta3N5 to yield active photoanodes that with NiOx retained 50-60% of their maximum photocurrent after 24 h chronoamperometry experiments and are thus among the most stable Ta3N5 photoanodes reported to date.

    View details for DOI 10.1021/acs.nanolett.6b03408

    View details for Web of Science ID 000389963200037

  • Microfabricated electrochemical gas sensor MICRO & NANO LETTERS Gross, P., Larsen, T., Loizeau, F., Jaramillo, T., Spitzer, D., Pruitt, B. 2016; 11 (12): 798-802
  • Mesoporous platinum nickel thin films with double gyroid morphology for the oxygen reduction reaction NANO ENERGY Kibsgaard, J., Jackson, A., Jaramillo, T. F. 2016; 29: 243-248
  • Solar water splitting by photovoltaic-electrolysis with a solar-to-hydrogen efficiency over 30. Nature communications Jia, J., Seitz, L. C., Benck, J. D., Huo, Y., Chen, Y., Ng, J. W., Bilir, T., Harris, J. S., Jaramillo, T. F. 2016; 7: 13237-?

    Abstract

    Hydrogen production via electrochemical water splitting is a promising approach for storing solar energy. For this technology to be economically competitive, it is critical to develop water splitting systems with high solar-to-hydrogen (STH) efficiencies. Here we report a photovoltaic-electrolysis system with the highest STH efficiency for any water splitting technology to date, to the best of our knowledge. Our system consists of two polymer electrolyte membrane electrolysers in series with one InGaP/GaAs/GaInNAsSb triple-junction solar cell, which produces a large-enough voltage to drive both electrolysers with no additional energy input. The solar concentration is adjusted such that the maximum power point of the photovoltaic is well matched to the operating capacity of the electrolysers to optimize the system efficiency. The system achieves a 48-h average STH efficiency of 30%. These results demonstrate the potential of photovoltaic-electrolysis systems for cost-effective solar energy storage.

    View details for DOI 10.1038/ncomms13237

    View details for PubMedID 27796309

    View details for PubMedCentralID PMC5095559

  • A highly active and stable IrOx/SrIrO3 catalyst for the oxygen evolution reaction SCIENCE Seitz, L. C., Dickens, C. F., Nishio, K., Hikita, Y., Montoya, J., Doyle, A., Kirk, C., Vojvodic, A., Hwang, H. Y., Norskov, J. K., Jaramillo, T. F. 2016; 353 (6303): 1011-1014

    Abstract

    Oxygen electrochemistry plays a key role in renewable energy technologies such as fuel cells and electrolyzers, but the slow kinetics of the oxygen evolution reaction (OER) limit the performance and commercialization of such devices. Here we report an iridium oxide/strontium iridium oxide (IrOx/SrIrO3) catalyst formed during electrochemical testing by strontium leaching from surface layers of thin films of SrIrO3 This catalyst has demonstrated specific activity at 10 milliamps per square centimeter of oxide catalyst (OER current normalized to catalyst surface area), with only 270 to 290 millivolts of overpotential for 30 hours of continuous testing in acidic electrolyte. Density functional theory calculations suggest the formation of highly active surface layers during strontium leaching with IrO3 or anatase IrO2 motifs. The IrOx/SrIrO3 catalyst outperforms known IrOx and ruthenium oxide (RuOx) systems, the only other OER catalysts that have reasonable activity in acidic electrolyte.

    View details for DOI 10.1126/science.aaf5050

    View details for Web of Science ID 000382558900034

    View details for PubMedID 27701108

  • Two-Dimensional Molybdenum Carbide (MXene) as an Efficient Electrocatalyst for Hydrogen Evolution ACS ENERGY LETTERS Seh, Z. W., Fredrickson, K. D., Anasori, B., Kibsgaard, J., Strickler, A. L., Lukatskaya, M. R., Gogotsi, Y., Jaramillo, T. F., Vojvodic, A. 2016; 1 (3): 589-594
  • Elucidating the electronic structure of supported gold nanoparticles and its relevance to catalysis by means of hard X-ray photoelectron spectroscopy SURFACE SCIENCE Reinecke, B. N., Kuhl, K. P., Ogasawara, H., Li, L., Voss, J., Abild-Pedersen, F., Nilsson, A., Jaramillo, T. F. 2016; 650: 24-33
  • Molybdenum Disulfide as a Protection Layer and Catalyst for Gallium Indium Phosphide Solar Water Splitting Photocathodes JOURNAL OF PHYSICAL CHEMISTRY LETTERS Britto, R. J., Benck, J. D., Young, J. L., Hahn, C., Deutsch, T. G., Jaramillo, T. F. 2016; 7 (11): 2044-2049

    Abstract

    Gallium indium phosphide (GaInP2) is a semiconductor with promising optical and electronic properties for solar water splitting, but its surface stability is problematic as it undergoes significant chemical and electrochemical corrosion in aqueous electrolytes. Molybdenum disulfide (MoS2) nanomaterials are promising to both protect GaInP2 and to improve catalysis because MoS2 is resistant to corrosion and also possesses high activity for the hydrogen evolution reaction (HER). In this work, we demonstrate that GaInP2 photocathodes coated with thin MoS2 surface protecting layers exhibit excellent activity and stability for solar hydrogen production, with no loss in performance (photocurrent onset potential, fill factor, and light-limited current density) after 60 h of operation. This represents a 500-fold increase in stability compared to bare p-GaInP2 samples tested in identical conditions.

    View details for DOI 10.1021/acs.jpclett.6b00563

    View details for Web of Science ID 000377239200018

    View details for PubMedID 27196435

  • Gold-supported cerium-doped NiOx catalysts for water oxidation NATURE ENERGY Ng, J. W., Garcia-Melchor, M., Bajdich, M., Chakthranont, P., Kirk, C., Vojvodic, A., Jaramillo, T. F. 2016; 1
  • Improving the Photoelectrochemical Performance of Hematite by Employing a High Surface Area Scaffold and Engineering Solid-Solid Interfaces ADVANCED MATERIALS INTERFACES Chakthranont, P., Pinaud, B. A., Seitz, L. C., Forman, A. J., Jaramillo, T. F. 2016; 3 (7)
  • Band Edge Engineering of Oxide Photoanodes for Photoelectrochemical Water Splitting: Integration of Subsurface Dipoles with Atomic-Scale Control ADVANCED ENERGY MATERIALS Hikita, Y., Nishio, K., Seitz, L. C., Chakthranont, P., Tachikawa, T., Jaramillo, T. F., Hwang, H. Y. 2016; 6 (7)
  • Hydrogen generation and fuel cells: Current status, research challenges, and future prospects Jaramillo, T. AMER CHEMICAL SOC. 2016
  • Tuning Composition and Activity of Cobalt Titanium Oxide Catalysts for the Oxygen Evolution Reaction ELECTROCHIMICA ACTA Seitz, L. C., Nordlund, D., Gallo, A., Jaramillo, T. F. 2016; 193: 240-245
  • Engineering Cobalt Phosphide (CoP) Thin Film Catalysts for Enhanced Hydrogen Evolution Activity on Silicon Photocathodes ADVANCED ENERGY MATERIALS Hellstern, T. R., Benck, J. D., Kibsgaard, J., Hahn, C., Jaramillo, T. F. 2016; 6 (4)
  • Chemical and Phase Evolution of Amorphous Molybdenum Sulfide Catalysts for Electrochemical Hydrogen Production. ACS nano Lee, S. C., Benck, J. D., Tsai, C., Park, J., Koh, A. L., Abild-Pedersen, F., Jaramillo, T. F., Sinclair, R. 2016; 10 (1): 624-632

    Abstract

    Amorphous MoSx is a highly active, earth-abundant catalyst for the electrochemical hydrogen evolution reaction. Previous studies have revealed that this material initially has a composition of MoS3, but after electrochemical activation, the surface is reduced to form an active phase resembling MoS2 in composition and chemical state. However, structural changes in the MoSx catalyst and the mechanism of the activation process remain poorly understood. In this study, we employ transmission electron microscopy (TEM) to image amorphous MoSx catalysts activated under two hydrogen-rich conditions: ex situ in an electrochemical cell and in situ in an environmental TEM. For the first time, we directly observe the formation of crystalline domains in the MoSx catalyst after both activation procedures as well as spatially localized changes in the chemical state detected via electron energy loss spectroscopy. Using density functional theory calculations, we investigate the mechanisms for this phase transformation and find that the presence of hydrogen is critical for enabling the restructuring process. Our results suggest that the surface of the amorphous MoSx catalyst is dynamic: while the initial catalyst activation forms the primary active surface of amorphous MoS2, continued transformation to the crystalline phase during electrochemical operation could contribute to catalyst deactivation. These results have important implications for the application of this highly active electrocatalyst for sustainable H2 generation.

    View details for DOI 10.1021/acsnano.5b05652

    View details for PubMedID 26624225

  • Benchmarking nanoparticulate metal oxide electrocatalysts for the alkaline water oxidation reaction JOURNAL OF MATERIALS CHEMISTRY A Jung, S., McCrory, C. C., Ferrer, I. M., Peters, J. C., Jaramillo, T. F. 2016; 4 (8): 3068-3076

    View details for DOI 10.1039/c5ta07586f

    View details for Web of Science ID 000371077300034

  • Electrooxidation of Alcohols with Electrode-Supported Transfer Hydrogenation Catalysts ACS CATALYSIS Buonaiuto, M., De Crisci, A. G., Jaramillo, T. F., Waymouth, R. M. 2015; 5 (12): 7343-7349
  • Enhancement Effect of Noble Metals on Manganese Oxide for the Oxygen Evolution Reaction JOURNAL OF PHYSICAL CHEMISTRY LETTERS Seitz, L. C., Hersbach, T. J., Nordlund, D., Jaramillo, T. F. 2015; 6 (20): 4178-4183

    Abstract

    Developing improved catalysts for the oxygen evolution reaction (OER) is key to the advancement of a number of renewable energy technologies, including solar fuels production and metal air batteries. In this study, we employ electrochemical methods and synchrotron techniques to systematically investigate interactions between metal oxides and noble metals that lead to enhanced OER catalysis for water oxidation. In particular, we synthesize porous MnOx films together with nanoparticles of Au, Pd, Pt, or Ag and observe significant improvement in activity for the combined catalysts. Soft X-ray absorption spectroscopy (XAS) shows that increased activity correlates with increased Mn oxidation states to 4+ under OER conditions compared to bare MnOx, which exhibits minimal OER current and remains in a 3+ oxidation state. Thickness studies of bare MnOx films and of MnOx films deposited on Au nanoparticles reveal trends suggesting that the enhancement in activity arises from interfacial sites between Au and MnOx.

    View details for DOI 10.1021/acs.jpclett.5b01928

    View details for Web of Science ID 000363083900031

  • Polymer Electrolyte Membrane Electrolyzers Utilizing Non-precious Mo-based Hydrogen Evolution Catalysts. ChemSusChem Ng, J. W., Hellstern, T. R., Kibsgaard, J., Hinckley, A. C., Benck, J. D., Jaramillo, T. F. 2015; 8 (20): 3512-3519

    Abstract

    The development of low-cost hydrogen evolution reaction (HER) catalysts that can be readily integrated into electrolyzers is critical if H2 from renewable electricity-powered electrolysis is to compete cost effectively with steam reforming. Herein, we report three distinct earth-abundant Mo-based catalysts, namely those based on MoSx , [Mo3 S13 ](2-) nanoclusters, and sulfur-doped Mo phosphide (MoP|S), loaded onto carbon supports. The catalysts were synthesized through facile impregnation-sulfidization routes specifically designed for catalyst-device compatibility. Fundamental electrochemical studies demonstrate the excellent HER activity and stability of the Mo-sulfide based catalysts in an acidic environment, and the resulting polymer electrolyte membrane (PEM) electrolyzers that integrate these catalysts exhibit high efficiency and durability. This work is an important step towards the goal of replacing Pt with earth-abundant catalysts for the HER in commercial PEM electrolyzers.

    View details for DOI 10.1002/cssc.201500334

    View details for PubMedID 26377877

  • Mapping Photoelectrochemical Current Distribution at Nanoscale Dimensions on Morphologically Controlled BiVO4 JOURNAL OF PHYSICAL CHEMISTRY LETTERS Chakthranont, P., Seitz, L. C., Jaramillo, T. F. 2015; 6 (18): 3702-3707

    Abstract

    We develop a method that can be used to qualitatively map photocurrent on photoelectrode surfaces, and show its utility for morphologically controlled W-doped BiVO4. The method is based on the deliberate photoinduced sintering of Au NPs, a photon-driven process that indicates oxidation with nanoscale-resolution. This strategy allows us to identify the active regions on W-doped BiVO4 photoelectrodes, and we observe a strong dependence of photoactivity on the electrode morphology, controlled by varying the relative humidity during the sol-gel fabrication process. We find that photoelectrode morphologies that exhibit the most evenly distributed Au sintering are those that yield the highest photoelectrochemical (PEC) activity. Understanding the correlation between electrode morphology and PEC activity is essential for designing structured semiconductors for PEC water splitting.

    View details for DOI 10.1021/acs.jpclett.5b01587

    View details for Web of Science ID 000361858800030

  • Platinum and hybrid polyaniline-platinum surfaces for the electrocatalytic reduction of CO2 MRS COMMUNICATIONS Abram, D. N., Kuhl, K. P., Cave, E. R., Jaramillo, T. F. 2015; 5 (2): 319-325
  • Benchmarking Hydrogen Evolving Reaction and Oxygen Evolving Reaction Electrocatalysts for Solar Water Splitting Devices JOURNAL OF THE AMERICAN CHEMICAL SOCIETY McCrory, C. C., Jung, S., Ferrer, I. M., Chatman, S. M., Peters, J. C., Jaramillo, T. F. 2015; 137 (13): 4347-4357

    Abstract

    Objective comparisons of electrocatalyst activity and stability using standard methods under identical conditions are necessary to evaluate the viability of existing electrocatalysts for integration into solar-fuel devices as well as to help inform the development of new catalytic systems. Herein, we use a standard protocol as a primary screen for evaluating the activity, short-term (2 h) stability, and electrochemically active surface area (ECSA) of 18 electrocatalysts for the hydrogen evolution reaction (HER) and 26 electrocatalysts for the oxygen evolution reaction (OER) under conditions relevant to an integrated solar water-splitting device in aqueous acidic or alkaline solution. Our primary figure of merit is the overpotential necessary to achieve a magnitude current density of 10 mA cm(-2) per geometric area, the approximate current density expected for a 10% efficient solar-to-fuels conversion device under 1 sun illumination. The specific activity per ECSA of each material is also reported. Among HER catalysts, several could operate at 10 mA cm(-2) with overpotentials <0.1 V in acidic and/or alkaline solutions. Among OER catalysts in acidic solution, no non-noble metal based materials showed promising activity and stability, whereas in alkaline solution many OER catalysts performed with similar activity achieving 10 mA cm(-2) current densities at overpotentials of ~0.33-0.5 V. Most OER catalysts showed comparable or better specific activity per ECSA when compared to Ir and Ru catalysts in alkaline solutions, while most HER catalysts showed much lower specific activity than Pt in both acidic and alkaline solutions. For select catalysts, additional secondary screening measurements were conducted including Faradaic efficiency and extended stability measurements.

    View details for DOI 10.1021/ja510442p

    View details for Web of Science ID 000352752000019

    View details for PubMedID 25668483

  • Semiconductor materials for efficient photoelectrochemical water splitting: The PEC working group Wang, H., Jaramillo, T., Miller, E. AMER CHEMICAL SOC. 2015
  • Enhancement Effect of Noble Metals on Manganese Oxide for the Oxygen Evolution Reaction. The journal of physical chemistry letters Seitz, L. C., Hersbach, T. J., Nordlund, D., Jaramillo, T. F. 2015; 6 (20): 4178–83

    Abstract

    Developing improved catalysts for the oxygen evolution reaction (OER) is key to the advancement of a number of renewable energy technologies, including solar fuels production and metal air batteries. In this study, we employ electrochemical methods and synchrotron techniques to systematically investigate interactions between metal oxides and noble metals that lead to enhanced OER catalysis for water oxidation. In particular, we synthesize porous MnOx films together with nanoparticles of Au, Pd, Pt, or Ag and observe significant improvement in activity for the combined catalysts. Soft X-ray absorption spectroscopy (XAS) shows that increased activity correlates with increased Mn oxidation states to 4+ under OER conditions compared to bare MnOx, which exhibits minimal OER current and remains in a 3+ oxidation state. Thickness studies of bare MnOx films and of MnOx films deposited on Au nanoparticles reveal trends suggesting that the enhancement in activity arises from interfacial sites between Au and MnOx.

    View details for PubMedID 26722794

  • Mapping Photoelectrochemical Current Distribution at Nanoscale Dimensions on Morphologically Controlled BiVO4. The journal of physical chemistry letters Chakthranont, P., Seitz, L. C., Jaramillo, T. F. 2015; 6 (18): 3702–7

    Abstract

    We develop a method that can be used to qualitatively map photocurrent on photoelectrode surfaces, and show its utility for morphologically controlled W-doped BiVO4. The method is based on the deliberate photoinduced sintering of Au NPs, a photon-driven process that indicates oxidation with nanoscale-resolution. This strategy allows us to identify the active regions on W-doped BiVO4 photoelectrodes, and we observe a strong dependence of photoactivity on the electrode morphology, controlled by varying the relative humidity during the sol-gel fabrication process. We find that photoelectrode morphologies that exhibit the most evenly distributed Au sintering are those that yield the highest photoelectrochemical (PEC) activity. Understanding the correlation between electrode morphology and PEC activity is essential for designing structured semiconductors for PEC water splitting.

    View details for PubMedID 26713778

  • Designing an improved transition metal phosphide catalyst for hydrogen evolution using experimental and theoretical trends ENERGY & ENVIRONMENTAL SCIENCE Kibsgaard, J., Tsai, C., Chan, K., Benck, J. D., Norskov, J. K., Abild-Pedersen, F., Jaramillo, T. F. 2015; 8 (10): 3022-3029

    View details for DOI 10.1039/c5ee02179k

    View details for Web of Science ID 000362351700024

  • CoTiOx Catalysts for the Oxygen Evolution Reaction JOURNAL OF THE ELECTROCHEMICAL SOCIETY Seitz, L. C., Pinaud, B. A., Nordlund, D., GORLIN, Y., Gallo, A., Jaramillo, T. F. 2015; 162 (12): H841-H846
  • Synthesis of thin film AuPd alloys and their investigation for electrocatalytic CO2 reduction JOURNAL OF MATERIALS CHEMISTRY A Hahn, C., Abram, D. N., Hansen, H. A., Hatsukade, T., Jackson, A., Johnson, N. C., Hellstern, T. R., Kuhl, K. P., Cave, E. R., Feaster, J. T., Jaramillo, T. F. 2015; 3 (40): 20185-20194

    View details for DOI 10.1039/c5ta04863j

    View details for Web of Science ID 000363151000021

  • Applications of ALD MnO to electrochemical water splitting PHYSICAL CHEMISTRY CHEMICAL PHYSICS Pickrahn, K. L., Gorlin, Y., Seitz, L. C., Garg, A., Nordlund, D., Jaramillo, T. F., Bent, S. F. 2015; 17 (21): 14003-14011

    Abstract

    Atomic layer deposition (ALD) is an attractive method to deposit uniform catalytic films onto high surface area electrodes. One interesting material for ALD synthesis is MnOx, a promising earth-abundant catalyst for the oxygen evolution reaction (OER). It has previously been shown that catalysts beginning as MnO synthesized using ALD on smooth glassy carbon (s-GC) electrodes and Mn2O3 obtained upon annealing MnO on s-GC are active OER catalysts. Here, we use ALD to deposit MnO on high surface area GC (HSA-GC) substrates, forming an active catalyst on a geometric surface area basis. We then characterize three types of catalysts, HSA-GC MnO, s-GC MnO, and annealed MnO (Mn2O3), using cyclic voltammetry (CV), scanning electron microscopy (SEM), and ex situ X-ray absorption spectroscopy (XAS). We show that under OER conditions, all three catalysts oxidize to similar surface states with a mixture of Mn(3+)/Mn(4+) and that MnOx surface area effects can account for the observed differences in the catalytic activity. We also demonstrate the need for a high surface area support for high OER activity on a geometric basis.

    View details for DOI 10.1039/c5cp00843c

    View details for Web of Science ID 000354946200025

    View details for PubMedID 25946998

  • Simultaneous detection of electronic structure changes from two elements of a bifunctional catalyst using wavelength-dispersive X-ray emission spectroscopy and in situ electrochemistry PHYSICAL CHEMISTRY CHEMICAL PHYSICS Gul, S., Ng, J. W., Alonso-Mori, R., Kern, J., Sokaras, D., Anzenberg, E., Lassalle-Kaiser, B., Gorlin, Y., Weng, T., Zwart, P. H., Zhang, J. Z., Bergmann, U., Yachandra, V. K., Jaramillo, T. F., Yano, J. 2015; 17 (14): 8901-8912

    Abstract

    Multielectron catalytic reactions, such as water oxidation, nitrogen reduction, or hydrogen production in enzymes and inorganic catalysts often involve multimetallic clusters. In these systems, the reaction takes place between metals or metals and ligands to facilitate charge transfer, bond formation/breaking, substrate binding, and release of products. In this study, we present a method to detect X-ray emission signals from multiple elements simultaneously, which allows for the study of charge transfer and the sequential chemistry occurring between elements. Kβ X-ray emission spectroscopy (XES) probes charge and spin states of metals as well as their ligand environment. A wavelength-dispersive spectrometer based on the von Hamos geometry was used to disperse Kβ signals of multiple elements onto a position detector, enabling an XES spectrum to be measured in a single-shot mode. This overcomes the scanning needs of the scanning spectrometers, providing data free from temporal and normalization errors and therefore ideal to follow sequential chemistry at multiple sites. We have applied this method to study MnOx-based bifunctional electrocatalysts for the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR). In particular, we investigated the effects of adding a secondary element, Ni, to form MnNiOx and its impact on the chemical states and catalytic activity, by tracking the redox characteristics of each element upon sweeping the electrode potential. The detection scheme we describe here is general and can be applied to time-resolved studies of materials consisting of multiple elements, to follow the dynamics of catalytic and electron transfer reactions.

    View details for DOI 10.1039/c5cp01023c

    View details for Web of Science ID 000351933600043

    View details for PubMedID 25747045

  • Designing Active and Stable Silicon Photocathodes for Solar Hydrogen Production Using Molybdenum Sulfide Nanomaterials ADVANCED ENERGY MATERIALS Benck, J. D., Lee, S. C., Fong, K. D., Kibsgaard, J., Sinclair, R., Jaramillo, T. F. 2014; 4 (18)
  • Molybdenum Phosphosulfide: An Active, Acid-Stable, Earth-Abundant Catalyst for the Hydrogen Evolution Reaction ANGEWANDTE CHEMIE-INTERNATIONAL EDITION Kibsgaard, J., Jaramillo, T. F. 2014; 53 (52): 14433-14437

    Abstract

    Introducing sulfur into the surface of molybdenum phosphide (MoP) produces a molybdenum phosphosulfide (MoP|S) catalyst with superb activity and stability for the hydrogen evolution reaction (HER) in acidic environments. The MoP|S catalyst reported herein exhibits one of the highest HER activities of any non-noble-metal electrocatalyst investigated in strong acid, while remaining perfectly stable in accelerated durability testing. Whereas mixed-metal alloy catalysts are well-known, MoP|S represents a more uncommon mixed-anion catalyst where synergistic effects between sulfur and phosphorus produce a high-surface-area electrode that is more active than those based on either the pure sulfide or the pure phosphide. The extraordinarily high activity and stability of this catalyst open up avenues to replace platinum in technologies relevant to renewable energies, such as proton exchange membrane (PEM) electrolyzers and solar photoelectrochemical (PEC) water-splitting cells.

    View details for DOI 10.1002/anie.201408222

    View details for Web of Science ID 000346485800022

    View details for PubMedID 25359678

  • Operando Characterization of an Amorphous Molybdenum Sulfide Nanoparticle Catalyst during the Hydrogen Evolution Reaction JOURNAL OF PHYSICAL CHEMISTRY C Casalongue, H. G., Benck, J. D., Tsai, C., Karlsson, R. K., Kaya, S., Ng, M. L., Pettersson, L. G., Abild-Pedersen, F., Norskov, J. K., Ogasawara, H., Jaramillo, T. F., Nilsson, A. 2014; 118 (50): 29252-29259

    View details for DOI 10.1021/jp505394e

    View details for Web of Science ID 000346759300037

  • Catalyzing the Hydrogen Evolution Reaction (HER) with Molybdenum Sulfide Nanonnaterials ACS CATALYSIS Benck, J. D., Hellstern, T. R., Kibsgaard, J., Chakthranont, P., Jaramillo, T. F. 2014; 4 (11): 3957-3971

    View details for DOI 10.1021/cs500923c

    View details for Web of Science ID 000344639300019

  • Substrate Selection for Fundamental Studies of Electrocatalysts and Photoelectrodes: Inert Potential Windows in Acidic, Neutral, and Basic Electrolyte PLOS ONE Benck, J. D., Pinaud, B. A., Gorlin, Y., Jaramillo, T. F. 2014; 9 (10)

    Abstract

    The selection of an appropriate substrate is an important initial step for many studies of electrochemically active materials. In order to help researchers with the substrate selection process, we employ a consistent experimental methodology to evaluate the electrochemical reactivity and stability of seven potential substrate materials for electrocatalyst and photoelectrode evaluation. Using cyclic voltammetry with a progressively increased scan range, we characterize three transparent conducting oxides (indium tin oxide, fluorine-doped tin oxide, and aluminum-doped zinc oxide) and four opaque conductors (gold, stainless steel 304, glassy carbon, and highly oriented pyrolytic graphite) in three different electrolytes (sulfuric acid, sodium acetate, and sodium hydroxide). We determine the inert potential window for each substrate/electrolyte combination and make recommendations about which materials may be most suitable for application under different experimental conditions. Furthermore, the testing methodology provides a framework for other researchers to evaluate and report the baseline activity of other substrates of interest to the broader community.

    View details for DOI 10.1371/journal.pone.0107942

    View details for Web of Science ID 000346765000003

    View details for PubMedID 25357131

    View details for PubMedCentralID PMC4214636

  • Optoelectronic properties of Ta3N5: A joint theoretical and experimental study PHYSICAL REVIEW B Morbec, J. M., Narkeviciute, I., Jaramillo, T. F., Galli, G. 2014; 90 (15)
  • Electrocatalytic Conversion of Carbon Dioxide to Methane and Methanol on Transition Metal Surfaces JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Kuhl, K. P., Hatsukade, T., Cave, E. R., Abram, D. N., Kibsgaard, J., Jaramillo, T. F. 2014; 136 (40): 14107-14113

    Abstract

    Fuels and industrial chemicals that are conventionally derived from fossil resources could potentially be produced in a renewable, sustainable manner by an electrochemical process that operates at room temperature and atmospheric pressure, using only water, CO2, and electricity as inputs. To enable this technology, improved catalysts must be developed. Herein, we report trends in the electrocatalytic conversion of CO2 on a broad group of seven transition metal surfaces: Au, Ag, Zn, Cu, Ni, Pt, and Fe. Contrary to conventional knowledge in the field, all metals studied are capable of producing methane or methanol. We quantify reaction rates for these two products and describe catalyst activity and selectivity in the framework of CO binding energies for the different metals. While selectivity toward methane or methanol is low for most of these metals, the fact that they are all capable of producing these products, even at a low rate, is important new knowledge. This study reveals a richer surface chemistry for transition metals than previously known and provides new insights to guide the development of improved CO2 conversion catalysts.

    View details for DOI 10.1021/ja505791r

    View details for Web of Science ID 000343026700028

  • Electrocatalytic conversion of carbon dioxide to methane and methanol on transition metal surfaces. Journal of the American Chemical Society Kuhl, K. P., Hatsukade, T., Cave, E. R., Abram, D. N., Kibsgaard, J., Jaramillo, T. F. 2014; 136 (40): 14107-14113

    Abstract

    Fuels and industrial chemicals that are conventionally derived from fossil resources could potentially be produced in a renewable, sustainable manner by an electrochemical process that operates at room temperature and atmospheric pressure, using only water, CO2, and electricity as inputs. To enable this technology, improved catalysts must be developed. Herein, we report trends in the electrocatalytic conversion of CO2 on a broad group of seven transition metal surfaces: Au, Ag, Zn, Cu, Ni, Pt, and Fe. Contrary to conventional knowledge in the field, all metals studied are capable of producing methane or methanol. We quantify reaction rates for these two products and describe catalyst activity and selectivity in the framework of CO binding energies for the different metals. While selectivity toward methane or methanol is low for most of these metals, the fact that they are all capable of producing these products, even at a low rate, is important new knowledge. This study reveals a richer surface chemistry for transition metals than previously known and provides new insights to guide the development of improved CO2 conversion catalysts.

    View details for DOI 10.1021/ja505791r

    View details for PubMedID 25259478

  • Nickel-silver alloy electrocatalysts for hydrogen evolution and oxidation in an alkaline electrolyte. Physical chemistry chemical physics Tang, M. H., Hahn, C., Klobuchar, A. J., Ng, J. W., Wellendorff, J., Bligaard, T., Jaramillo, T. F. 2014; 16 (36): 19250-19257

    Abstract

    The development of improved catalysts for the hydrogen evolution reaction (HER) and hydrogen oxidation reaction (HOR) in basic electrolytes remains a major technical obstacle to improved fuel cells, water electrolyzers, and other devices for electrochemical energy storage and conversion. Based on the free energy of adsorbed hydrogen intermediates, theory predicts that alloys of nickel and silver are active for these reactions. In this work, we synthesize binary nickel-silver bulk alloys across a range of compositions and show that nickel-silver alloys are indeed more active than pure nickel for hydrogen evolution and, possibly, hydrogen oxidation. To overcome the mutual insolubility of silver and nickel, we employ electron-beam physical vapor codeposition, a low-temperature synthetic route to metastable alloys. This method also produces flat and uniform films that facilitate the measurement of intrinsic catalytic activity with minimal variations in the surface area, ohmic contact, and pore transport. Rotating-disk-electrode measurements demonstrate that the hydrogen evolution activity per geometric area of the most active catalyst in this study, Ni0.75Ag0.25, is approximately twice that of pure nickel and has comparable stability and hydrogen oxidation activity. Our experimental results are supported by density functional theory calculations, which show that bulk alloying of Ni and Ag creates a variety of adsorption sites, some of which have near-optimal hydrogen binding energy.

    View details for DOI 10.1039/c4cp01385a

    View details for PubMedID 25098811

  • Engineering tantalum nitride photoanodes for improved activity and stability in photoelectrochemical (PEC) water splitting Narkeviciute, I., Pinaud, B. A., Jaramillo, T. F. AMER CHEMICAL SOC. 2014
  • Insights into the electrocatalytic reduction of CO2 on metallic silver surfaces. Physical chemistry chemical physics Hatsukade, T., Kuhl, K. P., Cave, E. R., Abram, D. N., Jaramillo, T. F. 2014; 16 (27): 13814-13819

    Abstract

    The electrochemical reduction of CO2 could allow for a sustainable process by which renewable energy from wind and solar are used directly in the production of fuels and chemicals. In this work we investigated the potential dependent activity and selectivity of the electrochemical reduction of CO2 on metallic silver surfaces under ambient conditions. Our results deepen our understanding of the surface chemistry and provide insight into the factors important to designing better catalysts for the reaction. The high sensitivity of our experimental methods for identifying and quantifying products of reaction allowed for the observation of six reduction products including CO and hydrogen as major products and formate, methane, methanol, and ethanol as minor products. By quantifying the potential-dependent behavior of all products, we provide insights into kinetics and mechanisms at play, in particular involving the production of hydrocarbons and alcohols on catalysts with weak CO binding energy as well as the formation of a C-C bond required to produce ethanol.

    View details for DOI 10.1039/c4cp00692e

    View details for PubMedID 24915537

  • A carbon-free, precious-metal-free, high-performance O-2 electrode for regenerative fuel cells and metal-air batteries ENERGY & ENVIRONMENTAL SCIENCE Ng, J. W., Tang, M., Jaramillo, T. F. 2014; 7 (6): 2017-2024

    View details for DOI 10.1039/c3ee44059a

    View details for Web of Science ID 000336831700025

  • Modeling practical performance limits of photoelectrochemical water splitting based on the current state of materials research. ChemSusChem Seitz, L. C., Chen, Z., Forman, A. J., Pinaud, B. A., Benck, J. D., Jaramillo, T. F. 2014; 7 (5): 1372-1385

    Abstract

    Photoelectrochemical (PEC) water splitting is a means to store solar energy in the form of hydrogen. Knowledge of practical limits for this process can help researchers assess their technology and guide future directions. We develop a model to quantify loss mechanisms in PEC water splitting based on the current state of materials research and calculate maximum solar-to-hydrogen (STH) conversion efficiencies along with associated optimal absorber band gaps. Various absorber configurations are modeled considering the major loss mechanisms in PEC devices. Quantitative sensitivity analyses for each loss mechanism and each absorber configuration show a profound impact of both on the resulting STH efficiencies, which can reach upwards of 25 % for the highest performance materials in a dual stacked configuration. Higher efficiencies could be reached as improved materials are developed. The results of the modeling also identify and quantify approaches that can improve system performance when working with imperfect materials.

    View details for DOI 10.1002/cssc.201301030

    View details for PubMedID 24692256

  • Understanding Interactions between Manganese Oxide and Gold That Lead to Enhanced Activity for Electrocatalytic Water Oxidation. Journal of the American Chemical Society Gorlin, Y., Chung, C., Benck, J. D., Nordlund, D., Seitz, L., Weng, T., Sokaras, D., Clemens, B. M., Jaramillo, T. F. 2014; 136 (13): 4920-4926

    Abstract

    To develop active nonprecious metal-based electrocatalysts for the oxygen evolution reaction (OER), a limiting reaction in several emerging renewable energy technologies, a deeper understanding of the activity of the first row transition metal oxides is needed. Previous studies of these catalysts have reported conflicting results on the influence of noble metal supports on the OER activity of the transition metal oxides. Our study aims to clarify the interactions between a transition metal oxide catalyst and its metal support in turning over this reaction. To achieve this goal, we examine a catalytic system comprising nanoparticulate Au, a common electrocatalytic support, and nanoparticulate MnOx, a promising OER catalyst. We conclusively demonstrate that adding Au to MnOx significantly enhances OER activity relative to MnOx in the absence of Au, producing an order of magnitude higher turnover frequency (TOF) than the TOF of the best pure MnOx catalysts reported to date. We also provide evidence that it is a local rather than bulk interaction between Au and MnOx that leads to the observed enhancement in the OER activity. Engineering improvements in nonprecious metal-based catalysts by the addition of Au or other noble metals could still represent a scalable catalyst as even trace amounts of Au are shown to lead a significant enhancement in the OER activity of MnOx.

    View details for DOI 10.1021/ja407581w

    View details for PubMedID 24661269

  • Insights into the electrochemical conversion of CO2 to hydrocarbons and alcohols on transition metals surfaces Jaramillo, T. F., Kuhl, K. P., Cave, E. R., Abram, D. N., Hatsukade, T., Hahn, C. J., Feaster, J., Kibsgaard, J. AMER CHEMICAL SOC. 2014
  • Building an appropriate active-site motif into a hydrogen-evolution catalyst with thiomolybdate [Mo3S13](2-) clusters. Nature chemistry Kibsgaard, J., Jaramillo, T. F., Besenbacher, F. 2014; 6 (3): 248-253

    Abstract

    Identifying and understanding the active sites responsible for reaction turnover is critical to developing improved catalysts. For the hydrogen-evolution reaction (HER), MoS2 has been identified as an active non-noble-metal-based catalyst. However, only edge sites turnover the reaction because the basal planes are catalytically inert. In an effort to develop a scalable HER catalyst with an increased number of active sites, herein we report a Mo-S catalyst (supported thiomolybdate [Mo3S13](2-) nanoclusters) in which most sulfur atoms in the structure exhibit a structural motif similar to that observed at MoS2 edges. Supported sub-monolayers of [Mo3S13](2-) nanoclusters exhibited excellent HER activity and stability in acid. Imaging at the atomic scale with scanning tunnelling microscopy allowed for direct characterization of these supported catalysts. The [Mo3S13](2-) nanoclusters reported herein demonstrated excellent turnover frequencies, higher than those observed for other non-precious metal catalysts synthesized by a scalable route.

    View details for DOI 10.1038/nchem.1853

    View details for PubMedID 24557141

  • Nearly Total Solar Absorption in Ultrathin Nanostructured Iron Oxide for Efficient Photoelectrochemical Water Splitting ACS PHOTONICS Wang, K. X., Wu, Z., Liu, V., Brongersma, M. L., Jaramillo, T. F., Fan, S. 2014; 1 (3): 235-240

    View details for DOI 10.1021/ph4001026

    View details for Web of Science ID 000335802900013

  • Controlling the Structural and Optical Properties of Ta3N5 Films through Nitridation Temperature and the Nature of the Ta Metal CHEMISTRY OF MATERIALS Pinaud, B. A., Vailionis, A., Jaramillo, T. F. 2014; 26 (4): 1576-1582

    View details for DOI 10.1021/cm403482s

    View details for Web of Science ID 000332059400012

  • High Surface Area Transparent Conducting Oxide Electrodes with a Customizable Device Architecture CHEMISTRY OF MATERIALS Forman, A. J., Chen, Z., Chakthranont, P., Jaramillo, T. F. 2014; 26 (2): 958-964

    View details for DOI 10.1021/cm402551m

    View details for Web of Science ID 000330543600012

  • Climbing the Activity Volcano: Core-Shell Ru@Pt Electrocatalysts for Oxygen Reduction CHEMELECTROCHEM Jackson, A., Viswanathan, V., Forman, A. J., Larsen, A. H., Norskov, J. K., Jaramillo, T. F. 2014; 1 (1): 67-71
  • Insights into the electrocatalytic reduction of CO2 on metallic silver surfaces PHYSICAL CHEMISTRY CHEMICAL PHYSICS Hatsukade, T., Kuhl, K. P., Cave, E. R., Abram, D. N., Jaramillo, T. F. 2014; 16 (27): 13814-13819

    Abstract

    The electrochemical reduction of CO2 could allow for a sustainable process by which renewable energy from wind and solar are used directly in the production of fuels and chemicals. In this work we investigated the potential dependent activity and selectivity of the electrochemical reduction of CO2 on metallic silver surfaces under ambient conditions. Our results deepen our understanding of the surface chemistry and provide insight into the factors important to designing better catalysts for the reaction. The high sensitivity of our experimental methods for identifying and quantifying products of reaction allowed for the observation of six reduction products including CO and hydrogen as major products and formate, methane, methanol, and ethanol as minor products. By quantifying the potential-dependent behavior of all products, we provide insights into kinetics and mechanisms at play, in particular involving the production of hydrocarbons and alcohols on catalysts with weak CO binding energy as well as the formation of a C-C bond required to produce ethanol.

    View details for DOI 10.1039/c4cp00692e

    View details for Web of Science ID 000338116700031

  • Perfect Sunlight Absorption in Iron Oxide Photoanode Wang, K., Yu, Z., Liu, V., Brongersma, M., Jaramillo, T., Fang, S., IEEE IEEE. 2014
  • Nanostructured Manganese Oxide Supported onto Particulate Glassy Carbon as an Active and Stable Oxygen Reduction Catalyst in Alkaline-Based Fuel Cells JOURNAL OF THE ELECTROCHEMICAL SOCIETY Ng, J. W., Gorlin, Y., Nordlund, D., Jaramillo, T. F. 2014; 161 (7): D3105-D3112
  • An X-ray Photoelectron Spectroscopy Study of Surface Changes on Brominated and Sulfur-Treated Activated Carbon Sorbents during Mercury Capture: Performance of Pellet versus Fiber Sorbents ENVIRONMENTAL SCIENCE & TECHNOLOGY Saha, A., Abram, D. N., Kuhl, K. P., Paradis, J., Crawford, J. L., Sasmaz, E., Chang, R., Jaramillo, T. F., Wilcox, J. 2013; 47 (23): 13695-13701

    Abstract

    This work explores surface changes and the Hg capture performance of brominated activated carbon (AC) pellets, sulfur-treated AC pellets, and sulfur-treated AC fibers upon exposure to simulated Powder River Basin-fired flue gas. Hg breakthrough curves yielded specific Hg capture amounts by means of the breakthrough shapes and times for the three samples. The brominated AC pellets showed a sharp breakthrough after 170-180 h and a capacity of 585 μg of Hg/g, the sulfur-treated AC pellets exhibited a gradual breakthrough after 80-90 h and a capacity of 661 μg of Hg/g, and the sulfur-treated AC fibers showed no breakthrough even after 1400 h, exhibiting a capacity of >9700 μg of Hg/g. X-ray photoelectron spectroscopy was used to analyze sorbent surfaces before and after testing to show important changes in quantification and oxidation states of surface Br, N, and S after exposure to the simulated flue gas. For the brominated and sulfur-treated AC pellet samples, the amount of surface-bound Br and reduced sulfur groups decreased upon Hg capture testing, while the level of weaker Hg-binding surface S(VI) and N species (perhaps as NH4(+)) increased significantly. A high initial concentration of strong Hg-binding reduced sulfur groups on the surface of the sulfur-treated AC fiber is likely responsible for this sorbent's minimal accumulation of S(VI) species during exposure to the simulated flue gas and is linked to its superior Hg capture performance compared to that of the brominated and sulfur-treated AC pellet samples.

    View details for DOI 10.1021/es403280z

    View details for PubMedID 24256554

  • A Precious-Metal-Free Regenerative Fuel Cell for Storing Renewable Electricity ADVANCED ENERGY MATERIALS Ng, J. W., Gorlin, Y., Hatsukade, T., Jaramillo, T. F. 2013; 3 (12): 1545-1550
  • Benchmarking Heterogeneous Electrocatalysts for the Oxygen Evolution Reaction JOURNAL OF THE AMERICAN CHEMICAL SOCIETY McCrory, C. C., Jung, S., Peters, J. C., Jaramillo, T. F. 2013; 135 (45): 16977-16987

    Abstract

    Objective evaluation of the activity of electrocatalysts for water oxidation is of fundamental importance for the development of promising energy conversion technologies including integrated solar water-splitting devices, water electrolyzers, and Li-air batteries. However, current methods employed to evaluate oxygen-evolving catalysts are not standardized, making it difficult to compare the activity and stability of these materials. We report a protocol for evaluating the activity, stability, and Faradaic efficiency of electrodeposited oxygen-evolving electrocatalysts. In particular, we focus on methods for determining electrochemically active surface area and measuring electrocatalytic activity and stability under conditions relevant to an integrated solar water-splitting device. Our primary figure of merit is the overpotential required to achieve a current density of 10 mA cm(-2) per geometric area, approximately the current density expected for a 10% efficient solar-to-fuels conversion device. Utilizing the aforementioned surface area measurements, one can determine electrocatalyst turnover frequencies. The reported protocol was used to examine the oxygen-evolution activity of the following systems in acidic and alkaline solutions: CoO(x), CoPi, CoFeO(x), NiO(x), NiCeO(x), NiCoO(x), NiCuO(x), NiFeO(x), and NiLaO(x). The oxygen-evolving activity of an electrodeposited IrO(x) catalyst was also investigated for comparison. Two general observations are made from comparing the catalytic performance of the OER catalysts investigated: (1) in alkaline solution, every non-noble metal system achieved 10 mA cm(-2) current densities at similar operating overpotentials between 0.35 and 0.43 V, and (2) every system but IrO(x) was unstable under oxidative conditions in acidic solutions.

    View details for DOI 10.1021/ja407115p

    View details for Web of Science ID 000327103600040

    View details for PubMedID 24171402

  • Impedance-based study of capacitive porous carbon electrodes with hierarchical and bimodal porosity JOURNAL OF POWER SOURCES Suss, M. E., Baumann, T. F., Worsley, M. A., Rose, K. A., Jaramillo, T. F., Stadermann, M., Santiago, J. G. 2013; 241: 266-273
  • Technical and economic feasibility of centralized facilities for solar hydrogen production via photocatalysis and photoelectrochemistry ENERGY & ENVIRONMENTAL SCIENCE Pinaud, B. A., Benck, J. D., Seitz, L. C., Forman, A. J., Chen, Z., Deutsch, T. G., James, B. D., Baum, K. N., Baum, G. N., Ardo, S., Wang, H., Miller, E., Jaramillo, T. F. 2013; 6 (7): 1983-2002

    View details for DOI 10.1039/c3ee40831k

    View details for Web of Science ID 000320779700001

  • In Situ X-ray Absorption Spectroscopy Investigation of a Bifunctional Manganese Oxide Catalyst with High Activity for Electrochemical Water Oxidation and Oxygen Reduction. Journal of the American Chemical Society Gorlin, Y., Lassalle-Kaiser, B., Benck, J. D., Gul, S., Webb, S. M., Yachandra, V. K., Yano, J., Jaramillo, T. F. 2013; 135 (23): 8525-8534

    Abstract

    In situ X-ray absorption spectroscopy (XAS) is a powerful technique that can be applied to electrochemical systems, with the ability to elucidate the chemical nature of electrocatalysts under reaction conditions. In this study, we perform in situ XAS measurements on a bifunctional manganese oxide (MnOx) catalyst with high electrochemical activity for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). Using X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), we find that exposure to an ORR-relevant potential of 0.7 V vs RHE produces a disordered Mn3(II,III,III)O4 phase with negligible contributions from other phases. After the potential is increased to a highly anodic value of 1.8 V vs RHE, relevant to the OER, we observe an oxidation of approximately 80% of the catalytic thin film to form a mixed Mn(III,IV) oxide, while the remaining 20% of the film consists of a less oxidized phase, likely corresponding to unchanged Mn3(II,III,III)O4. XAS and electrochemical characterization of two thin film catalysts with different MnOx thicknesses reveals no significant influence of thickness on the measured oxidation states, at either ORR or OER potentials, but demonstrates that the OER activity scales with film thickness. This result suggests that the films have porous structure, which does not restrict electrocatalysis to the top geometric layer of the film. As the portion of the catalyst film that is most likely to be oxidized at the high potentials necessary for the OER is that which is closest to the electrolyte interface, we hypothesize that the Mn(III,IV) oxide, rather than Mn3(II,III,III)O4, is the phase pertinent to the observed OER activity.

    View details for DOI 10.1021/ja3104632

    View details for PubMedID 23758050

  • Bridging the Gap Between Bulk and Nanostructured Photoelectrodes: The Impact of Surface States on the Electrocatalytic and Photoelectrochemical Properties of MoS2 JOURNAL OF PHYSICAL CHEMISTRY C Chen, Z., Forman, A. J., Jaramillo, T. F. 2013; 117 (19): 9713-9722

    View details for DOI 10.1021/jp311375k

    View details for Web of Science ID 000319649100020

  • Benchmarking electrocatalysts for hydrogen evolution and oxygen evolution McCrory, C. L., Jung, S., Peters, J. C., Jaramillo, T. F. AMER CHEMICAL SOC. 2013
  • Growth of Pt Nanowires by Atomic Layer Deposition on Highly Ordered Pyrolytic Graphite NANO LETTERS Lee, H., Baeck, S. H., Jaramillo, T. F., Bent, S. F. 2013; 13 (2): 457-463

    Abstract

    The formation of Pt nanowires (NWs) by atomic layer deposition on highly ordered pyrolytic graphite (HOPG) is investigated. Pt is deposited only at the step edges of HOPG and not on the basal planes, leading to the formation of laterally aligned Pt NWs. A growth model involving a morphological transition from 0-D to 1-D structures via coalescence is presented. The width of the NWs grows at a rate greater than twice the vertical growth rate. This asymmetry is ascribed to the wetting properties of Pt on HOPG as influenced by the formation of graphene oxide. A difference in Pt growth kinetics based on crystallographic orientation may also contribute.

    View details for DOI 10.1021/nl303803p

    View details for Web of Science ID 000315079500021

    View details for PubMedID 23317031

  • Catalyzing chemical transformations in renewable energy: Tailoring Electrocatalyst Materials for Activity, Selectivity, and Stability Jaramillo, T., F. 2013
  • Effect of Temperature Treatment on CoTiOx Catalyst for the Oxygen Evolution Reaction 2nd International Symposium on Electrochemical Synthesis of Fuels (ESF) Seitz, L. C., Pinaud, B. A., Nordlund, D., Jaramillo, T. F. ELECTROCHEMICAL SOC INC. 2013: 285–91
  • Solar hydrogen production by photoelectrochemical (PEC) water-splitting: Advancing technology through the synergistic activities of the PEC working group (PEC WG) Jaramillo, T., F. 2013
  • Exploring Nano-architectures of MoS2: How Surface Structure and Electronic Structure Impact H2 Production by Electrocatalysis and Solar Photoelectrochemistry Jaramillo, T., F. 2013
  • Catalyzing Electrochemical Transformations in Renewable Energy Jaramillo, T., F. 2013
  • The Impact of Surface Structure on the Electrocatalytic and Photoelectrochemical (PEC) Properties of MoS2 Jaramillo, T., F. 2013
  • Electrocatalytic Conversion of Carbon Dioxide to Fuels and Chemicals on Transition Metal Electrodes Jaramillo, T., F., Kuhl, K., P., Cave, E., R., Abram, D., N., Hatsukade, T. 2013
  • Catalyzing key chemical transformations for renewable, sustainable energy Jaramillo, T., F. 2013
  • Mn3O4 Supported on Glassy Carbon: An Active Non-Precious Metal Catalyst for the Oxygen Reduction Reaction ACS CATALYSIS Gorlin, Y., Chung, C., Nordlund, D., Clemens, B. M., Jaramillo, T. F. 2012; 2 (12): 2687-2694

    View details for DOI 10.1021/cs3004352

    View details for Web of Science ID 000312170100030

  • Engineering the surface structure of MoS2 to preferentially expose active edge sites for electrocatalysis NATURE MATERIALS Kibsgaard, J., Chen, Z., Reinecke, B. N., Jaramillo, T. F. 2012; 11 (11): 963-969

    Abstract

    Controlling surface structure at the atomic scale is paramount to developing effective catalysts. For example, the edge sites of MoS(2) are highly catalytically active and are thus preferred at the catalyst surface over MoS(2) basal planes, which are inert. However, thermodynamics favours the presence of the basal plane, limiting the number of active sites at the surface. Herein, we engineer the surface structure of MoS(2) to preferentially expose edge sites to effect improved catalysis by successfully synthesizing contiguous large-area thin films of a highly ordered double-gyroid MoS(2) bicontinuous network with nanoscaled pores. The high surface curvature of this catalyst mesostructure exposes a large fraction of edge sites, which, along with its high surface area, leads to excellent activity for electrocatalytic hydrogen evolution. This work elucidates how morphological control of materials at the nanoscale can significantly impact the surface structure at the atomic scale, enabling new opportunities for enhancing surface properties for catalysis and other important technological applications.

    View details for DOI 10.1038/NMAT3439

    View details for Web of Science ID 000310434600021

    View details for PubMedID 23042413

  • New cubic perovskites for one- and two-photon water splitting using the computational materials repository ENERGY & ENVIRONMENTAL SCIENCE Castelli, I. E., Landis, D. D., Thygesen, K. S., Dahl, S., Chorkendorff, I., Jaramillo, T. F., Jacobsen, K. W. 2012; 5 (10): 9034-9043

    View details for DOI 10.1039/c2ee22341d

    View details for Web of Science ID 000308891200029

  • Active MnOx Electrocatalysts Prepared by Atomic Layer Deposition for Oxygen Evolution and Oxygen Reduction Reactions ADVANCED ENERGY MATERIALS Pickrahn, K. L., Park, S. W., Gorlin, Y., Lee, H., Jaramillo, T. F., Bent, S. F. 2012; 2 (10): 1269-1277
  • Mercury chemistry on brominated activated carbon FUEL Sasmaz, E., Kirchofer, A., Jew, A. D., Saha, A., Abram, D., Jaramillo, T. F., Wilcox, J. 2012; 99: 188-196
  • Amorphous Molybdenum Sulfide Catalysts for Electrochemical Hydrogen Production: Insights into the Origin of their Catalytic Activity ACS CATALYSIS Benck, J. D., Chen, Z., Kuritzky, L. Y., Forman, A. J., Jaramillo, T. F. 2012; 2 (9): 1916-1923

    View details for DOI 10.1021/cs300451q

    View details for Web of Science ID 000308577300011

  • Effect of Film Morphology and Thickness on Charge Transport in Ta3N5/Ta Photoanodes for Solar Water Splitting JOURNAL OF PHYSICAL CHEMISTRY C Pinaud, B. A., Vesborg, P. C., Jaramillo, T. F. 2012; 116 (30): 15918-15924

    View details for DOI 10.1021/jp3041742

    View details for Web of Science ID 000306989500007

  • Meso-Structured Platinum Thin Films: Active and Stable Electrocatalysts for the Oxygen Reduction Reaction JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Kibsgaard, J., Gorlin, Y., Chen, Z., Jaramillo, T. F. 2012; 134 (18): 7758-7765

    Abstract

    Improving both the activity and the stability of the cathode catalyst in platinum-based polymer electrolyte fuel cells is a key technical challenge. Here, we synthesize a high surface area meso-structured Pt thin film that exhibits higher specific activity for the oxygen reduction reaction (ORR) than commercial carbon-supported Pt nanoparticles (Pt/C). An accelerated stability test demonstrates that the meso-structured Pt thin film also displays significantly enhanced stability as compared to the commercial Pt/C catalyst. Our study reveals the origin of the high turnover frequency (TOF), and excellent durability is attributed to the meso-structure, which yields a morphology with fewer undercoordinated Pt sites than Pt/C nanoparticles, a key difference with substantial impact to the surface chemistry. The improved catalyst activity and stability could enable the development of a high-performance gas diffusion electrode that is resistant to corrosion even under the harsh conditions of start-up, shut-down, and/or hydrogen starvation.

    View details for DOI 10.1021/ja2120162

    View details for Web of Science ID 000303696200035

    View details for PubMedID 22500676

  • New insights into the electrochemical reduction of carbon dioxide on metallic copper surfaces ENERGY & ENVIRONMENTAL SCIENCE Kuhl, K. P., Cave, E. R., Abram, D. N., Jaramillo, T. F. 2012; 5 (5): 7050-7059

    View details for DOI 10.1039/c2ee21234j

    View details for Web of Science ID 000303251500047

  • Simulating Linear Sweep Voltammetry from First-Principles: Application to Electrochemical Oxidation of Water on Pt(111) and Pt3Ni(111) JOURNAL OF PHYSICAL CHEMISTRY C Viswanathan, V., Hansen, H. A., Rossmeisl, J., Jaramillo, T. F., Pitsch, H., Norskov, J. K. 2012; 116 (7): 4698-4704

    View details for DOI 10.1021/jp210802q

    View details for Web of Science ID 000301156500043

  • Identifying active surface phases for metal oxide electrocatalysts: a study of manganese oxide bi-functional catalysts for oxygen reduction and water oxidation catalysis PHYSICAL CHEMISTRY CHEMICAL PHYSICS Su, H., Gorlin, Y., Man, I. C., Calle-Vallejo, F., Norskov, J. K., Jaramillo, T. F., Rossmeisl, J. 2012; 14 (40): 14010-14022

    Abstract

    Progress in the field of electrocatalysis is often hampered by the difficulty in identifying the active site on an electrode surface. Herein we combine theoretical analysis and electrochemical methods to identify the active surfaces in a manganese oxide bi-functional catalyst for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). First, we electrochemically characterize the nanostructured α-Mn(2)O(3) and find that it undergoes oxidation in two potential regions: initially, between 0.5 V and 0.8 V, a potential region relevant to the ORR and, subsequently, between 0.8 V and 1.0 V, a potential region between the ORR and the OER relevant conditions. Next, we perform density function theory (DFT) calculations to understand the changes in the MnO(x) surface as a function of potential and to elucidate reaction mechanisms that lead to high activities observed in the experiments. Using DFT, we construct surface Pourbaix and free energy diagrams of three different MnO(x) surfaces and identify 1/2 ML HO* covered Mn(2)O(3) and O* covered MnO(2), as the active surfaces for the ORR and the OER, respectively. Additionally, we find that the ORR occurs through an associative mechanism and that its overpotential is highly dependent on the stabilization of intermediates through hydrogen bonds with water molecules. We also determine that OER occurs through direct recombination mechanism and that its major source of overpotential is the scaling relationship between HOO* and HO* surface intermediates. Using a previously developed Sabatier model we show that the theoretical predictions of catalytic activities match the experimentally determined onset potentials for the ORR and the OER, both qualitatively and quantitatively. Consequently, the combination of first-principles theoretical analysis and experimental methods offers an understanding of manganese oxide oxygen electrocatalysis at the atomic level, achieving fundamental insight that can potentially be used to design and develop improved electrocatalysts for the ORR and the OER and other important reactions of technological interest.

    View details for DOI 10.1039/c2cp40841d

    View details for Web of Science ID 000309140400036

    View details for PubMedID 22990481

  • Tailoring electrocatalyst materials to enhance activity, stability, and selectivity for key energy conversion reactions Jaramillo, T., F. 2012
  • Electrocatalysis 101 Jaramillo, T., F. 2012
  • Developing Electrocatalysts for the Synthesis of Renewable Fuels Jaramillo, T., F. 2012
  • Catalyzing chemical transformations in renewable energy: Tailoring electrocatalyst materials for activity, selectivity, and stability Jaramillo, T., F. 2012
  • The electrocatalytic conversion of CO2 to fuels and chemicals Jaramillo, T., F., Kuhl, Kendra, P., Cave, Etosha, R., Abram, David, N. 2012
  • Tailoring electrocatalyst materials to enhance activity, stability, and selectivity for key energy conversion reactions Jaramillo, T., F. 2012
  • Tailoring electrocatalyst materials to enhance activity, stability, and selectivity for key energy conversion reactions Jaramillo, T., F. 2012
  • Engineering the Surface Structure of MoS2 Through Morphological Control At the Nano-Scale for Enhanced Electrocatalytic Hydrogen Production Jaramillo, T., F., Chen, Z., Kibsgaard, J., Reinecke, B., N. 2012
  • Bridging the gap between optical absorption and charge transport in metal oxide materials for the synthesis of solar fuels Jaramillo, T., F., Forman, A., J., Chen, Z., Thomann, I., Pinaud, B., A., Cho, I., S. 2012
  • Tailoring Electrocatalyst Materials at the Nano-Scale: Controlling Activity, Selectivity, and Stability for Energy Conversion Reactions Jaramillo, T., F. 2012
  • Tailoring Electrocatalyst Materials at the Nano-Scale: Controlling Activity, Selectivity, and Stability for Energy Conversion Reactions Jaramillo, T., F. 2012
  • Solar Fuels by Photocatalysis and Photoelectrochemistry Jaramillo, T., F. 2012
  • Insights into the electrochemical conversion of CO2 to fuels and chemicals on transition metal surfaces Jaramillo, T., F., Kuhl, K., P., Cave, E., R., Abram, D., N., Hatsukade, T. 2012
  • Directed Nano-scale and Macro-scale Architectures for Semiconductor Absorbers and Transparent Conducting Substrates for Photoelectrochemical Water Splitting Jaramillo, T., F., Forman, A., Chen, Z., Pinaud, B., A., Seitz, L., Jackson, A. 2012
  • Addressing charge transport limitations in thin film Ta3N5 & TaON photoanodes for solar fuel synthesis Jaramillo, T., F., Pinaud, B., A. 2012
  • Energy Storage by Means of Renewable Fuels Jaramillo, T., F. 2012
  • Electrocatalyst development for renewable energy: Engineering surface structure at the atomic-scale by controlling morphology at the nano-scale Jaramillo, T., F. 2012
  • Tailoring Electrocatalyst Materials at the Nano-Scale: Controlling Activity, Selectivity, and Stability for Energy Conversion Reactions Jaramillo, T., F. 2012
  • Electrocatalyst development for the synthesis of renewable fuels from water and CO2 Jaramillo, T., F. 2012
  • A tutorial on electrocatalysis: Concepts, fundamentals, methods, and applications Jaramillo, T., F. 2012
  • Addressing the terawatt challenge: scalability in the supply of chemical elements for renewable energy RSC ADVANCES Vesborg, P. C., Jaramillo, T. F. 2012; 2 (21): 7933-7947

    View details for DOI 10.1039/c2ra20839c

    View details for Web of Science ID 000307792200001

  • Investigation of Surface Oxidation Processes on Manganese Oxide Electrocatalysts Using Electrochemical Methods and Ex Situ X-ray Photoelectron Spectroscopy JOURNAL OF THE ELECTROCHEMICAL SOCIETY Gorlin, Y., Jaramillo, T. F. 2012; 159 (10): H782-H786
  • Branched TiO2 Nanorods for Photoelectrochemical Hydrogen Production NANO LETTERS Cho, I. S., Chen, Z., Forman, A. J., Kim, D. R., Rao, P. M., Jaramillo, T. F., Zheng, X. 2011; 11 (11): 4978-4984

    Abstract

    We report a hierarchically branched TiO(2) nanorod structure that serves as a model architecture for efficient photoelectrochemical devices as it simultaneously offers a large contact area with the electrolyte, excellent light-trapping characteristics, and a highly conductive pathway for charge carrier collection. Under Xenon lamp illumination (UV spectrum matched to AM 1.5G, 88 mW/cm(2) total power density), the branched TiO(2) nanorod array produces a photocurrent density of 0.83 mA/cm(2) at 0.8 V versus reversible hydrogen electrode (RHE). The incident photon-to-current conversion efficiency reaches 67% at 380 nm with an applied bias of 0.6 V versus RHE, nearly two times higher than the bare nanorods without branches. The branches improve efficiency by means of (i) improved charge separation and transport within the branches due to their small diameters, and (ii) a 4-fold increase in surface area which facilitates the hole transfer at the TiO(2)/electrolyte interface.

    View details for DOI 10.1021/nl2029392

    View details for Web of Science ID 000296674700082

    View details for PubMedID 21999403

  • Core-shell MoO3-MoS2 Nanowires for Hydrogen Evolution: A Functional Design for Electrocatalytic Materials NANO LETTERS Chen, Z., Cummins, D., Reinecke, B. N., Clark, E., Sunkara, M. K., Jaramillo, T. F. 2011; 11 (10): 4168-4175

    Abstract

    We synthesize vertically oriented core-shell nanowires with substoichiometric MoO(3) cores of ∼20-50 nm and conformal MoS(2) shells of ∼2-5 nm. The core-shell architecture, produced by low-temperature sulfidization, is designed to utilize the best properties of each component material while mitigating their deficiencies. The substoichiometric MoO(3) core provides a high aspect ratio foundation and enables facile charge transport, while the conformal MoS(2) shell provides excellent catalytic activity and protection against corrosion in strong acids.

    View details for DOI 10.1021/nl2020476

    View details for Web of Science ID 000295667000024

    View details for PubMedID 21894935

  • Plasmon Enhanced Solar-to-Fuel Energy Conversion NANO LETTERS Thomann, I., Pinaud, B. A., Chen, Z., Clemens, B. M., Jaramillo, T. F., Brongersma, M. L. 2011; 11 (8): 3440-3446

    Abstract

    Future generations of photoelectrodes for solar fuel generation must employ inexpensive, earth-abundant absorber materials in order to provide a large-scale source of clean energy. These materials tend to have poor electrical transport properties and exhibit carrier diffusion lengths which are significantly shorter than the absorption depth of light. As a result, many photoexcited carriers are generated too far from a reactive surface and recombine instead of participating in solar-to-fuel conversion. We demonstrate that plasmonic resonances in metallic nanostructures and multilayer interference effects can be engineered to strongly concentrate sunlight close to the electrode/liquid interface, precisely where the relevant reactions take place. On comparison of spectral features in the enhanced photocurrent spectra to full-field electromagnetic simulations, the contribution of surface plasmon excitations is verified. These results open the door to the optimization of a wide variety of photochemical processes by leveraging the rapid advances in the field of plasmonics.

    View details for DOI 10.1021/nl201908s

    View details for Web of Science ID 000293665600066

    View details for PubMedID 21749077

  • Universality in Oxygen Evolution Electrocatalysis on Oxide Surfaces CHEMCATCHEM Man, I. C., Su, H., Calle-Vallejo, F., Hansen, H. A., Martinez, J. I., Inoglu, N. G., Kitchin, J., Jaramillo, T. F., Norskov, J. K., Rossmeisl, J. 2011; 3 (7): 1159-1165
  • Thin Films of Sodium Birnessite-Type MnO2: Optical Properties, Electronic Band Structure, and Solar Photoelectrochemistry JOURNAL OF PHYSICAL CHEMISTRY C Pinaud, B. A., Chen, Z., Abram, D. N., Jaramillo, T. F. 2011; 115 (23): 11830-11838

    View details for DOI 10.1021/jp200015p

    View details for Web of Science ID 000291339000063

  • Electrocatalysis on manganese oxide surfaces: Oxygen reduction and water oxidation 241st National Meeting and Exposition of the American-Chemical-Society (ACS) Jaramillo, T. F., Gorlin, Y., Baeck, S., Pinaud, B. A. AMER CHEMICAL SOC. 2011
  • Ex-situ Spectroscopy Study of Manganese Oxide Catalytic Surfaces under Reaction Conditions Relevant to Oxygen Reduction and Oxygen Evolution 11th Polymer Electrolyte Fuel Cell Symposium (PEFC) Under the Auspices of the 220th Meeting of the ECS GORLIN, Y., Jaramillo, T. F. ELECTROCHEMICAL SOC INC. 2011: 1701–7

    View details for DOI 10.1149/1.3635701

    View details for Web of Science ID 000309598800163

  • Tailoring Electrocatalyst Materials at the Nano-Scale: Controlling Activity, Selectivity, and Stability for Energy Conversion Reactions Jaramillo, T., F. 2011
  • Nanostructured electrocatalysts for energy conversion reactions Jaramillo, T., F. 2011
  • Nanomaterials for efficient chemical transformations in energy conversion reactions Jaramillo, T., F. 2011
  • Catalyzing the production of clean fuels from renewable energy resources Jaramillo, T., F. 2011
  • Tailoring electrocatalyst materials at the nano-scale: Controlling activity, selectivity, and stability for energy conversion reactions Jaramillo, T., F. 2011
  • Tailoring Electrocatalyst Materials at the Nano-Scale: Controlling Activity, Selectivity, and Stability for Energy Conversion Reactions Jaramillo, T., F. 2011
  • Nano-architectures for 3rd generation PEC devices: A study of MoS2, fundamental investigations and applied research Jaramillo, T., F. 2011
  • Engineering catalysts at the nano-scale for energy conversion reactions Jaramillo, T., F. 2011
  • Tailoring electrocatalyst materials at the nano-scale: Controlling activity and selectivity for energy conversion reactions Jaramillo, T., F. 2011
  • Tailoring electrocatalyst materials at the nano-scale: Controlling activity and selectivity for energy conversion reactions Jaramillo, T., F. 2011
  • Semiconductors and catalysts for the production of solar fuels Jaramillo, T., F. 2011
  • Non-precious metal catalysts for electrochemical transformations between H2, O2, and H2O Jaramillo, T., F. 2011
  • Electrocatalytic conversion of CO2 to fuels on metal surfaces Jaramillo, T., F. 2011
  • Electrocatalytic Conversion of CO2 to Fuels on Metal Surfaces Jaramillo, T., F., Kuhl, K., P., Cave, E., Abram, D., N. 2011
  • Tailoring Electrocatalyst Materials at the Nano-Scale: Controlling Activity, Selectivity, and Stability for Energy Conversion Reactions Jaramillo, T., F. 2011
  • Tailoring electrocatalyst materials at the nano-scale: Controlling activity and selectivity for energy conversion reactions Jaramillo, T., F. 2011
  • Tailoring electrocatalyst materials at the nano-scale: Controlling activity and selectivity for energy conversion reactions Jaramillo, T., F. 2011
  • Nanostructured Catalysts for Chemical Transformations in Energy Jaramillo, T., F. 2011
  • Advanced electrode and photo-electrode structures for the synthesis of fuels from sunlight Jaramillo, T., F., Forman, A., J., Chen, Z., Pinaud, B., A., Benck, J., D., Baeck, S., H. 2011
  • Double Gyroid Nanostructured Platinum As Highly Durable Oxygen Reduction Reaction Electrocatalyst Jaramillo, T., F., Kibsgaard, J., Gorlin, Y. 2011
  • A Bifunctional Nonprecious Metal Catalyst for Oxygen Reduction and Water Oxidation JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Gorlin, Y., Jaramillo, T. F. 2010; 132 (39): 13612-13614

    Abstract

    There is a growing interest in oxygen electrochemistry as conversions between O(2) and H(2)O play an important role in a variety of renewable energy technologies. The goal of this work is to develop active bifunctional catalyst materials for water oxidation and oxygen reduction. Drawing inspiration from a cubane-like CaMn(4)O(x), the biological catalyst found in the oxygen evolving center (OEC) in photosystem II, nanostructured manganese oxide surfaces were investigated for these reactions. Thin films of nanostructured manganese oxide were found to be active for both oxygen reduction and water oxidation, with similar overall oxygen electrode activity to the best known precious metal nanoparticle catalysts: platinum, ruthenium, and iridium. Physical and chemical characterization of the nanostructured Mn oxide bifunctional catalyst reveals an oxidation state of Mn(III), akin to one of the most commonly observed Mn oxidation states found in the OEC.

    View details for DOI 10.1021/ja104587v

    View details for Web of Science ID 000282864100017

    View details for PubMedID 20839797

  • Nanostructured MoS2 for solar hydrogen production Chen, Z., Choi, S., Kibsgaard, J., Jaramillo, T. F. AMER CHEMICAL SOC. 2010
  • Accelerating materials development for photoelectrochemical hydrogen production: Standards for methods, definitions, and reporting protocols JOURNAL OF MATERIALS RESEARCH Chen, Z., Jaramillo, T. F., Deutsch, T. G., Kleiman-Shwarsctein, A., Forman, A. J., Gaillard, N., Garland, R., Takanabe, K., Heske, C., Sunkara, M., McFarland, E. W., Domen, K., Miller, E. L., Turner, J. A., Dinh, H. N. 2010; 25 (1): 3-16
  • Developing solid-state electrocatalysts based on design principles from nature: The oxidation of water and the reduction of CO2 to fuels Jaramillo, T., F. 2010
  • Nanostructured MoS2 and WS2 for the solar production of hydrogen Jaramillo, T., F. 2010
  • Nano-structured materials for the synthesis of fuels from sunlight Jaramillo, T., F. 2010
  • Surface electrocatalysis for fuel synthesis: Inspiration from nature Jaramillo, T., F. 2010
  • Nano-scaled materials for the synthesis of fuels from sunlight Jaramillo, T., F. 2010
  • Nano-scaled materials for the synthesis of fuels from sunlight Jaramillo, T., F. 2010
  • Nano-scaled materials for the synthesis of fuels from sunlight Jaramillo, T., F. 2010
  • Nano-scaled materials for the synthesis of fuels from sunlight Jaramillo, T., F. 2010
  • In pursuit of a reversible oxygen electrode: Water oxidation and oxygen reduction on electro-catalytic oxide surfaces Jaramillo, T., F. 2010
  • Bi-functional electrocatalysis on manganese oxide surfaces: oxygen reduction and water oxidation Jaramillo, T., F. 2010
  • Nanostructuring MoS2 for Photoelectrochemical Water Splitting Conference on Solar Hydrogen and Nanotechnology V Chen, Z., Kibsgaard, J., Jaramillo, T. F. SPIE-INT SOC OPTICAL ENGINEERING. 2010

    View details for DOI 10.1117/12.860659

    View details for Web of Science ID 000286094200009

  • Monolithic III-V Nanowire PV for Photoelectrochemical Hydrogen Generation 35th IEEE Photovoltaic Specialists Conference Ba, X., Pinaud, B. A., Parker, J., Aloni, S., Jaramillo, T. F., Wong, H. P. IEEE. 2010: 1793–1796
  • Alloys of platinum and early transition metals as oxygen reduction electrocatalysts NATURE CHEMISTRY Greeley, J., Stephens, I. E., Bondarenko, A. S., Johansson, T. P., Hansen, H. A., Jaramillo, T. F., Rossmeisl, J., Chorkendorff, I., Norskov, J. K. 2009; 1 (7): 552-556

    Abstract

    The widespread use of low-temperature polymer electrolyte membrane fuel cells for mobile applications will require significant reductions in the amount of expensive Pt contained within their cathodes, which drive the oxygen reduction reaction (ORR). Although progress has been made in this respect, further reductions through the development of more active and stable electrocatalysts are still necessary. Here we describe a new set of ORR electrocatalysts consisting of Pd or Pt alloyed with early transition metals such as Sc or Y. They were identified using density functional theory calculations as being the most stable Pt- and Pd-based binary alloys with ORR activity likely to be better than Pt. Electrochemical measurements show that the activity of polycrystalline Pt(3)Sc and Pt(3)Y electrodes is enhanced relative to pure Pt by a factor of 1.5-1.8 and 6-10, respectively, in the range 0.9-0.87 V.

    View details for DOI 10.1038/NCHEM.367

    View details for Web of Science ID 000270077200014

    View details for PubMedID 21378936

  • Combined spectroscopy and microscopy of supported MoS2 nanoparticles SURFACE SCIENCE Nielsen, J. H., Bech, L., Nielsen, K., Tison, Y., Jorgensen, K. P., Bonde, J. L., Horch, S., Jaramillo, T. F., Chorkendorff, I. 2009; 603 (9): 1182-1189
  • Electrocatalytic Activity of Gold-Platinum Clusters for Low Temperature Fuel Cell Applications JOURNAL OF PHYSICAL CHEMISTRY C Tang, W., Jayaraman, S., Jaramillo, T. F., Stucky, G. D., McFarland, E. W. 2009; 113 (12): 5014-5024

    View details for DOI 10.1021/jp8089209

    View details for Web of Science ID 000264349100044

  • Dynamics of Surface Exchange Reactions Between Au and Pt for HER and HOR JOURNAL OF THE ELECTROCHEMICAL SOCIETY Abrams, B. L., Vesborg, P. C., Bonde, J. L., Jaramillo, T. F., Chorkendorff, I. 2009; 156 (2): B273-B282

    View details for DOI 10.1149/1.3040509

    View details for Web of Science ID 000261973600018

  • Photon absorbers and energy conversion catalysts: New approaches to solar fuels Jaramillo, T., F. 2009
  • Nanostructured MoS2 for the Photoelectrochemical Production of Hydrogen Jaramillo, T., F. 2009
  • Nanostructured MoS2 and WS2 for the solar production of hydrogen Jaramillo, T., F. 2009
  • Nanostructured MoS2 and WS2 for the solar production of hydrogen Jaramillo, T., F. 2009
  • Nanostructured MoS2 and WS2 for the solar production of hydrogen Jaramillo, T., F. 2009
  • Nano-scaled semiconductors and novel catalysts for the synthesis of fuels from sunlight Jaramillo, T., F. 2009
  • Designing new electrocatalysts: A case study of the hydrogen evolution reaction (HER) Jaramillo, T., F. 2009
  • Electrocatalytic activity of gold-platinum clusters for low temperature fuel cell applications Journal of Physical Chemistry C Tang, W., Jayaraman, S., Jaramillo, T., F., Stucky, G., D., McFarland, E., W. 2009; 113 (12): 5014-5024
  • Combined spectroscopy and microscopy of supported MoS2 nanoparticles Surface Science Nielsen, J., H., Jørgensen, K., P., Bonde, J., Nielsen, K., Bech, L., Tison, Y., Jaramillo, T. F. 2009; 603 (9): 1182-1189
  • Alloys of platinum and early transition metals as oxygen reduction electrocatalysts Nature Chemistry Greeley, J., Stephens, I., E.L., Bondarenko, A., S., Johansson, T., P., Hansen, H., A., Jaramillo, T., F. 2009; 1 (7): 552-556
  • Designing new electrocatalysts for the hydrogen evolution reaction (HER): combining theory and experiment Jaramillo, T., F., Jørgensen, K., P., Bonde, J., Greeley, J., Zhang, J., Ooi, B., L. 2009
  • Solar Fuels by Photoelectrochemistry (PEC) Jaramillo, T., F. 2009
  • Nano-structured MoS2 and WS2 for the Solar Production of Hydrogen Jaramillo, T., F. 2009
  • Nano-scaled materials for the synthesis of fuels from sunlight Jaramillo, T., F. 2009
  • Designing nano-scaled, non-precious metal catalysts for hydrogen evolution Jaramillo, T., F., Jørgensen, K., P., Bonde, J., Greeley, J., Zhang, J., Ooi, B., L. 2009
  • Nano-scaled materials for the synthesis of fuels from sunlight Jaramillo, T., F. 2009
  • The Dynamics of Surface Exchange Reactions Between Au and Pt for the Hydrogen Evolution Reaction (HER) and the Hydrogen Oxidation Reaction (HOR) Journal of the Electrochemical Society Abrams, B., L., Vesborg, P., C.K., Bonde, J., Jaramillo, T., F., Chorkendorff, I. 2009; 156 (2): B273-B282
  • Hydrogen Evolution on Supported Incomplete Cubane-type [Mo3S4](4+) Electrocatalysts JOURNAL OF PHYSICAL CHEMISTRY C Jaramillo, T. F., Bonde, J., Zhang, J., Ooi, B., Andersson, K., Ulstrup, J., Chorkendorff, I. 2008; 112 (45): 17492-17498

    View details for DOI 10.1021/jp802695e

    View details for Web of Science ID 000260675900002

  • Hydrogen evolution on nano-particulate transition metal sulfides Conference on Electrocatalysis Theory and Experiment at the Interface Bonde, J., Moses, P. G., Jaramillo, T. F., Norskov, J. K., Chorkendorff, I. ROYAL SOC CHEMISTRY. 2008: 219–231

    Abstract

    The hydrogen evolution reaction (HER) on carbon supported MoS2 nanoparticles is investigated and compared to findings with previously published work on Au(111) supported MoS2. An investigation into MoS2 oxidation is presented and used to quantify the surface concentration of MoS2. Other metal sulfides with morphologies similar to MoS2 such as WS2, cobalt-promoted WS2, and cobalt-promoted MoS2 were also investigated in the search for improved HER activity. Experimental findings are compared to density functional theory (DFT) calculated values for the hydrogen binding energies (deltaGH) on each system.

    View details for DOI 10.1039/b803857k

    View details for Web of Science ID 000260437800016

    View details for PubMedID 19213319

  • Steady state oxygen reduction and cyclic voltammetry Conference on Electrocatalysis Theory and Experiment at the Interface Rossmeisl, J., Karlberg, G. S., Jaramillo, T., Norskov, J. K. ROYAL SOC CHEMISTRY. 2008: 337–346

    Abstract

    The catalytic activity of Pt and Pt3Ni for the oxygen reduction reaction is investigated by applying a Sabatier model based on density functional calculations. We investigate the role of adsorbed OH on the activity, by comparing cyclic voltammetry obtained from theory with previously published experimental results with and without molecular oxygen present. We find that the simple Sabatier model predicts both the potential dependence of the OH coverage and the measured current densities seen in experiments, and that it offers an understanding of the oxygen reduction reaction (ORR) at the atomic level. To investigate kinetic effects we develop a simple kinetic model for ORR. Whereas kinetic corrections only matter close to the volcano top, an interesting outcome of the kinetic model is a first order dependence on the oxygen pressure. Importantly, the conclusion obtained from the simple Sabatier model still persists: an intermediate binding of OH corresponds to the highest catalytic activity, i.e. Pt is limited by a too strong OH binding and Pt3Ni is limited by a too weak OH binding.

    View details for DOI 10.1039/b802129e

    View details for Web of Science ID 000260437800023

    View details for PubMedID 19213325

  • Designing novel electrocatalytic materials: a case study of the hydrogen evolution reaction (HER). Jaramillo, T., F., Jørgensen, K., P., Bonde, J., Nielsen, J., H., Chorkendorff, I., Horch, S. 2008
  • Designing electrocatalysts for the hydrogen evolution reaction. Jaramillo, T., F. 2008
  • Steady state oxygen reduction reaction and cyclic voltammetry Rossmeisl, J., Karlberg, G., S., Jaramillo, T., F., Nørskov, J., K 2008
  • Solar fuels by photoelectrochemistry: Prospects and challenges. Jaramillo, T., F. 2008
  • Precious-metal and non-precious metal based nano-scale electrocatalysts for electrocatalytic hydrogen evolution. Jaramillo, T., F., Ulstrup, J., Nørskov, J., K., Chorkendorff, I. 2008
  • New materials for electrocatalytic hydrogen production: from alloys to nanoparticles Jaramillo, T., F., Jørgensen, K., P., Bonde, J., Horch, S., Nielsen, J., H., Chorkendorff, I. 2008
  • Developing new hydrogen evolution electrocatalysts: metal surface alloys and nano-scale molybdenum sulfides. Jaramillo, T., F., Jørgensen, K., P., Bonde, J., Nielsen, J., H., Horch, S., Nørskov, J., K. 2008
  • Designing new electrocatalytic materials for the hydrogen evolution reaction (HER). Jaramillo, T., F. 2008
  • Electrocatalytic materials for the hydrogen evolution reaction. Jaramillo, T., F. 2008
  • Designing non-noble metal electrocatalysts: An investigation of the hydrogen evolution reaction. Jaramillo, T., F. 2008
  • Non-precious metal electrocatalysts for the hydrogen evolution reaction (HER): Inspiration for designing new PEC materials Jaramillo, T., F. 2008
  • In the pursuit of active, non-precious metal electrocatalysts: A study of the hydrogen evolution reaction (HER). Jaramillo, T., F., Jørgensen, K., P., Bonde, J., Nielsen, J., H., Chorkendorff, I., Horch, S. 2008
  • Cyclic voltammograms for H on Pt(111) and Pt(100) from first principles PHYSICAL REVIEW LETTERS Karlberg, G. S., Jaramillo, T. F., Skulason, E., Rossmeisl, J., Bligaard, T., Norskov, J. K. 2007; 99 (12)

    Abstract

    Cyclic voltammetry is a fundamental experimental method for characterizing electrochemical surfaces. Despite its wide use, a way to quantitatively and directly relate cyclic voltammetry to ab initio calculations has been lacking. We derive the cyclic voltammogram for H on Pt(111) and Pt(100), based solely on density functional theory calculations and standard molecular tables. By relating the gas phase adsorption energy to the electrochemical electrode potential, we provide a direct link between surface science and electrochemistry.

    View details for DOI 10.1103/PhysRevLett.99.126101

    View details for Web of Science ID 000249668000046

    View details for PubMedID 17930522

  • Identification of active edge sites for electrochemical H-2 evolution from MoS2 nanocatalysts SCIENCE Jaramillo, T. F., Jorgensen, K. P., Bonde, J., Nielsen, J. H., Horch, S., Chorkendorff, I. 2007; 317 (5834): 100-102

    Abstract

    The identification of the active sites in heterogeneous catalysis requires a combination of surface sensitive methods and reactivity studies. We determined the active site for hydrogen evolution, a reaction catalyzed by precious metals, on nanoparticulate molybdenum disulfide (MoS2) by atomically resolving the surface of this catalyst before measuring electrochemical activity in solution. By preparing MoS2 nanoparticles of different sizes, we systematically varied the distribution of surface sites on MoS2 nanoparticles on Au(111), which we quantified with scanning tunneling microscopy. Electrocatalytic activity measurements for hydrogen evolution correlate linearly with the number of edge sites on the MoS2 catalyst.

    View details for DOI 10.1126/science.1141483

    View details for Web of Science ID 000247776700058

    View details for PubMedID 17615351

  • From theory to experiment: New electrocatalysts for the hydrogen evolution reaction Jaramillo, T., F., Jørgensen, K., P., Bonde, J., Greeley, J., Nielsen, J., H., Horch, S. 2007
  • Nano-scale molybdenum sulfides for electrocatalytic hydrogen evolution Jaramillo, T., F., Jørgensen, K., P., Bonde, J., Horch, S., Nielsen, J., H., Chorkendorff, I. 2007
  • From alloys to bio-mimetic materials: searching for new hydrogen evolution electrocatalysts Jaramillo, T., F., Jørgensen, K., P., Bonde, J., Greeley, J., Saadi, S., Fernandez, E. 2007
  • Identification of Active Edge Sites for Electrochemical H2 Evolution from MoS2 Nanocatalysts Science Jaramillo, T., F., Jørgensen, K., P., Bonde, J., Nielsen, J., H., Horch, S., Chorkendorff, I. 2007; 317 (5834): 100-102
  • Cyclic voltammograms for H on Pt(111) and Pt(100) from first principles Physical Review Letters Karlberg, G., S., Jaramillo, T., F., Skúlason, E., Rossmeisl, J., Bligaard, T., Nørskov, J., K. 2007; 99 (126101)
  • Computational high-throughput screening of electrocatalytic materials for hydrogen evolution NATURE MATERIALS Greeley, J., Jaramillo, T. F., Bonde, J., Chorkendorff, I. B., Norskov, J. K. 2006; 5 (11): 909-913

    Abstract

    The pace of materials discovery for heterogeneous catalysts and electrocatalysts could, in principle, be accelerated by the development of efficient computational screening methods. This would require an integrated approach, where the catalytic activity and stability of new materials are evaluated and where predictions are benchmarked by careful synthesis and experimental tests. In this contribution, we present a density functional theory-based, high-throughput screening scheme that successfully uses these strategies to identify a new electrocatalyst for the hydrogen evolution reaction (HER). The activity of over 700 binary surface alloys is evaluated theoretically; the stability of each alloy in electrochemical environments is also estimated. BiPt is found to have a predicted activity comparable to, or even better than, pure Pt, the archetypical HER catalyst. This alloy is synthesized and tested experimentally and shows improved HER performance compared with pure Pt, in agreement with the computational screening results.

    View details for DOI 10.1038/nmat1752

    View details for Web of Science ID 000241732000026

    View details for PubMedID 17041585

  • New electrode materials for hydrogen production: A focus on nanoparticulate molybdenum sulfides Jaramillo, T., F., Jørgensen, K., P., Saadi, S., Bonde, J., Fernandez, E., Zhang, J. 2006
  • Low-voltage electrodeposition of fullerol thin films from aqueous solutions JOURNAL OF THE ELECTROCHEMICAL SOCIETY Kleiman-Shwarsctein, A., Jaramillo, T. F., Baeck, S., Sushchikh, M., McFarland, E. W. 2006; 153 (7): C483-C487

    View details for DOI 10.1149/1.2196671

    View details for Web of Science ID 000237945300037

  • New materials for hydrogen production: Nanoparticulate molybdenum sulfides Jaramillo, T., F., Jørgensen, K., P., Saadi, S., Bonde, J., Fernandez, E., Zhang, J. 2006
  • Electrocatalysis at nanometer and sub-nanometer scales: Hydrogen evolution on supported MoS2 and Mo3S4 clusters Jaramillo, T., F., Jørgensen, K., P., Saadi, S., Bonde, J., Fernandez, E., Zhang, J. 2006
  • Low-voltage electrodeposition of fullerol thin films from aqueous solutions Journal of the Electrochemical Society Kleiman-Shwarsctein, A., Jaramillo, T., F., Baeck, S., H., Sushchikh, M., McFarland, E., W. 2006; 153 (7): C483-C487
  • New materials for hydrogen evolution: From alloys to nanoparticles Jaramillo, T., F., Jørgensen, K., P., Bonde, J., Greeley, J., Nielsen, J., H., Horch, S. 2006
  • Nanoparticulate MoS2 electrocatalysts for hydrogen evolution Jaramillo, T., F., Jørgensen, K., P., Bonde, J., Horch, S., Nielsen, J., H., Chorkendorff, I. 2006
  • Biocatalysis and biomimetics for electrochemical hydrogen conversion. Electrocatalysis at the sub-nanometer scale: structure and function of supported Mo3S4 clusters Jaramillo, T., F., Saadi, S., Bonde, J., Zhang, J., Kristensen, J., Ooi, B., L. 2006
  • Computational high-throughput screening of electrocatalytic materials for hydrogen evolution Nature Materials Greeley, J., Jaramillo, T., F., Bonde, J., Chorkendorff, I., Nørskov, J., K. 2006; 5 (11): 909-913
  • Synthesis and characterization of Pt-WO3 as methanol oxidation catalysts for fuel cells JOURNAL OF PHYSICAL CHEMISTRY B Jayaraman, S., Jaramillo, T. F., Baeck, S. H., McFarland, E. W. 2005; 109 (48): 22958-22966

    Abstract

    Several compositions of Pt-WO3 catalysts were synthesized and characterized for the electro-oxidation of methanol and CO. The surface morphologies of the catalysts were found to be dependent on the composition. X-ray energy dispersive spectroscopy and X-ray photoelectron spectroscopy results suggest a surface enrichment of WO3 in the codeposited Pt-WO3 catalysts. Cyclic voltammetry and chronoamperometry in methanol show an improvement in catalytic activity for the Pt-WO3 catalysts. A significant improvement in the poison tolerance toward CO and other organic intermediates was observed in the mixed metal-metal oxide catalyst. The catalytic performance of the different compositions was directly compared by normalization of the current to active sites. CO-stripping voltammetry suggests the involvement of WO3 in the catalytic process as opposed to a mere physical effect as suggested by previous work. A possible mechanism for this improvement is proposed based on the electrochemical data.

    View details for DOI 10.1021/jp053053h

    View details for Web of Science ID 000233761300035

    View details for PubMedID 16853991

  • Combinatorial electrochemical synthesis and screening of Pt-WO3 catalysts for electro-oxidation of methanol REVIEW OF SCIENTIFIC INSTRUMENTS Jayaraman, S., Baeck, S. H., Jaramillo, T. F., Kleiman-Shwarsctein, A., McFarland, E. W. 2005; 76 (6)

    View details for DOI 10.1063/1.1927007

    View details for Web of Science ID 000229962000029

  • Synthesis of Au nanoclusters supported upon a TiO2 nanotube array JOURNAL OF MATERIALS RESEARCH Liu, X., Jaramillo, T. F., Kolmakov, A., Baeck, S. H., Moskovits, M., Stucky, G. D., McFarland, E. W. 2005; 20 (5): 1093-1096
  • Automated electrochemical synthesis and photoelectrochemical characterization of Zn1-xCoxO thin films for solar hydrogen production JOURNAL OF COMBINATORIAL CHEMISTRY Jaramillo, T. F., Baeck, S. H., Kleiman-Shwarsctein, A., Choi, K. S., Stucky, G. D., McFarland, E. W. 2005; 7 (2): 264-271

    Abstract

    High-throughput electrochemical methods have been developed for the investigation of Zn1-xCo(x)O films for photoelectrochemical hydrogen production from water. A library of 120 samples containing 27 different compositions (0

    View details for DOI 10.1021/cc049864x

    View details for Web of Science ID 000227708100015

    View details for PubMedID 15762755

  • Combinatorial electrochemical synthesis and screening of Pt-WO3 catalysts for electro-oxidation of methanol Review of Scientific Instruments Jayaraman, S., Baeck, S., H., Jaramillo, T., F., Kleiman-Shwarsctein, A., McFarland, E., W. 2005; 76 (6)
  • Automated electrochemical synthesis and characterization of TiO2 supported Au nanoparticle electrocatalysts MEASUREMENT SCIENCE & TECHNOLOGY Baeck, S. H., Jaramillo, T. F., Kleiman-Shwarsctein, A., McFarland, E. W. 2005; 16 (1): 54-59
  • High-throughput methods for the investigation of photoelectrochemical hydrogen production from Zn1-xCoxO thin films Jaramillo, T., F., Baeck, S., H., Kleiman-Shwarsctein, A., McFarland, E., W. 2005
  • Mixed-metal nanoparticles for fuel cell catalysis Jaramillo, T., F., Jayaraman, S., McFarland, E., W. 2005
  • Combinatorial Discovery: New Materials for Photoelectrochemical Hydrogen Production Jaramillo, T., F., Baeck, S., H., Kleiman-Shwarsctein, A., McFarland, E., W. 2005
  • Synthesis and characterization of Pt-WO3 films as methanol oxidation catalysts for low-temperature polymer electrolyte membrane fuel cells Journal of Physical Chemistry B Jayaraman, S., Jaramillo, T., F., Baeck, S., H., McFarland, E., W. 2005; 109 (48): 22958-22966
  • Optimized Materials for Photoelectrochemical Hydrogen Production Jaramillo, T., F. 2005
  • New materials for energy conversion reactions: photoelectrochemical hydrogen production and electrocatalytic methanol oxidation Jaramillo, T., F., Jayaraman, S., Baeck, S.-H, Kleiman-Shwarsctein, A., McFarland, E., W. 2005
  • Automated electrochemical synthesis and photoelectrochemical characterization of Zn1-xCoxO thin films for solar hydrogen production Journal of Combinatorial Chemistry Jaramillo, T., F., Baeck, S., H., Kleiman-Shwarsctein, A., Choi, K., S., Stucky, G., D., McFarland, E., W. 2005; 7 (2): 264-271
  • Automated electrochemical synthesis and characterization of TiO2 supported Au nanoparticle electrocatalysts Measurement Science & Technology Baeck, S., H., Jaramillo, T., F., Kleiman-Shwarsctein, A., McFarland, E., W. 2005; 16 (1): 54-59
  • Photoelectrochemical hydrogen production: a combinatorial investigation of ZnO-based materials Jaramillo, T., F., Baeck, S.-H, Kleiman-Shwarsctein, A., McFarland, E., W. 2005
  • New materials for photoelectrochemical hydrogen production: A high-throughput investigation Jaramillo, T., F., Baeck, S.-H, Kleiman-Shwarsctein, A., McFarland, E., W. 2005
  • High throughput investigation of new materials for the photoelectrochemical production of hydrogen Jaramillo, T., F., Baeck, S., H., Kleiman-Shwarsctein, A., McFarland, E., W. 2005
  • Doped semiconductors and mixed-metal nanoparticles: New materials for energy conversion reactions Jaramillo, T., F., Jayaraman, S., Baeck, S., H., Kleiman-Shwarsctein, A., McFarland, E., W. 2005
  • Synthesis of titania nanotubes with supported Au nanoclusters Journal of Materials Research Liu, X., Jaramillo, T., F., Kolmokov, A., Baeck, S., H., Moskovits, M., Stucky, G. 2005; 20 (5): 1093-1096
  • Gas-phase catalysis by micelle derived Au nanoparticles on oxide supports CATALYSIS LETTERS Chou, J., Franklin, N. R., Baeck, S. H., Jaramillo, T. F., McFarland, E. W. 2004; 95 (3-4): 107-111
  • Parallel synthesis and characterization of photoelectrochemically and electrochromically active tungsten-molybdenum oxides CHEMICAL COMMUNICATIONS Baeck, S. H., Jaramillo, T. F., Jeong, D. H., McFarland, E. W. 2004: 390-391

    Abstract

    Single phase tungsten-molybdenum mixed oxide films (W(1-x)Mo(x)O(3)) were successfully synthesized by automated parallel electrodeposition, and distinct structural changes were observed as a function of composition. A monoclinic structure (beta-phase) was observed in mixed oxides with less than 90% Mo, and above 90% Mo, orthorhombic structure (alpha-phase) was identified.

    View details for DOI 10.1039/b313924g

    View details for Web of Science ID 000220108100017

    View details for PubMedID 14765223

  • Combinatorial electrochemical synthesis and screening of mesoporous ZnO for photocatalysis Workshop on Combinatorial and High-Throughput Approaches in Polymer and Materials Science Jaramillo, T. F., Baeck, S. H., Kleiman-Shwarsctein, A., McFarland, E. W. WILEY-V C H VERLAG GMBH. 2004: 297–301
  • Combinatorial electrochemical synthesis and screening of mesoporous ZnO for photocatalysis Macromolecular Rapid Communications Jaramillo, T., F., Baeck, S., H., Kleiman-Shwarsctein, A., McFarland, E., W. 2004; 25 (1): 297-301
  • Structure, composition, and morphology of photoelectrochemically active TiO2-xNx thin films deposited by reactive DC magnetron sputtering Journal of Physical Chemistry B Mwabora, J., M., Lindgren, T., Avendaño, E., Jaramillo, T, .F., Lu, J., Lindquist, S., E. 2004; 108 (52): 20193-20198
  • Parallel synthesis and characterization of photoelectrochemically and electrochromically active tungsten molybdenum oxides Chemical Communications Baeck, S., H., Jaramillo, T., F., Jeong, D., H., McFarland, E., W. 2004; 4: 390-391
  • Size- and support-dependent electronic and catalytic properties of Au-0/Au3+ nanoparticles synthesized from block copolymer micelles JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Cuenya, B. R., Baeck, S. H., Jaramillo, T. F., McFarland, E. W. 2003; 125 (42): 12928-12934

    Abstract

    Supported Au nanoclusters synthesized from diblock copolymer micelles can be reliably prepared with well-controlled sizes and dispersions. For particles with diameters between approximately 1 and 6 nm, the particle size and the support were found to strongly influence the oxygen reactivity, the formation and stabilization of a metal-oxide, and the catalytic activity for electrooxidation of carbon monoxide. The smallest particles studied (1.5 nm) were the most active for electrooxidation of CO and had the largest fraction of oxygen associated with gold at the surface as measured by the Au(3+)/Au(0) X-ray photoemission intensities. Conducting and semiconducting substrates, ITO-coated glass and TiO(2), respectively, were associated with greater stabilization of Au(3+) oxide as compared to insulating, SiO(2), substrates.

    View details for DOI 10.1021/ja036468u

    View details for Web of Science ID 000185990300053

    View details for PubMedID 14558841

  • Synthesis of tungsten oxide on copper surfaces by electroless deposition CHEMISTRY OF MATERIALS Baeck, S. H., Jaramillo, T. F., Stucky, G. D., McFarland, E. W. 2003; 15 (18): 3411-3413

    View details for DOI 10.1021/cm0341641

    View details for Web of Science ID 000185221500003

  • Enhancement of photocatalytic and electrochromic properties of electrochemically fabricated mesoporous WO3 thin films ADVANCED MATERIALS Baeck, S. H., Choi, K. S., Jaramillo, T. F., Stucky, G. D., McFarland, E. W. 2003; 15 (15): 1269-?
  • Catalytic activity of supported au nanoparticles deposited from block copolymer micelles JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Jaramillo, T. F., Baeck, S. H., Cuenya, B. R., McFarland, E. W. 2003; 125 (24): 7148-7149

    Abstract

    Quasi-ordered, highly dispersed, gold nanoclusters of tightly controlled particle size were synthesized by dip-coating substrates with gold precursors encapsulated by block-copolymer micelles. By this method, gold particles (4.8 +/- 1.3 nm) were deposited on ITO-coated glass and shown to be catalytically active for electro-oxidation of carbon monoxide. XPS confirmed the catalytically active particles were predominantly Au0; however, a large fraction existed as Au3+. Whereas bulk gold is inert, these results demonstrate that catalytically active Au nanoparticles can be derived from micelle encapsulation.

    View details for Web of Science ID 000183503500002

    View details for PubMedID 12797767

  • A CU2O/TiO2 heterojunction thin film cathode for photoelectrocatalysis SOLAR ENERGY MATERIALS AND SOLAR CELLS Siripala, W., Ivanovskaya, A., Jaramillo, T. F., Baeck, S. H., McFarland, E. W. 2003; 77 (3): 229-237
  • Catalytic activity of supported Au nanoparticles deposited from block copolymer micelles Journal of the American Chemical Society Jaramillo, T., F., Baeck, S., H., Roldan-Cuenya, B., McFarland, E., W. 2003; 125 (24): 7148-7149
  • Photoelectrochemical Hydrogen Production Using New Combinatorial Chemistry Derived Materials Jaramillo, T., F., Baeck, S.-H, Kleiman-Shwarsctein, A., McFarland, E., W. 2003
  • Combinatorial Investigation of New Materials for Photoelectrochemical Hydrogen Production Jaramillo, T., F., Baeck, S., H., Kleiman-Shwarsctein, A., Choi, K.-S, Stucky, G., D., McFarland, E., W. 2003
  • A Cu2O/TiO2 heterojunction thin film cathode for photoelectrocatalysis Solar Energy Materials and Solar Cells Siripala, W., Ivanovskaya, A., Jaramillo, T., F., Baeck, S., H., McFarland, E., W. 2003; 77 (3): 229-237
  • Size and support dependent electronic and catalytic properties of Au0/Au3+ nanoparticles synthesized from block co-polymer micelles Journal of the American Chemical Society Roldan-Cuenya, B., Baeck, S., H., Jaramillo, T., F., McFarland, E., W. 2003; 125 (42): 12928-12934
  • Combinatorial Electrochemical Synthesis and Screening of Transition-Metal Doped Zinc Oxides as Water-Splitting Photocatalysts for H2 Production Jaramillo, T., F., Choi, K.-S, Baeck, S., H., McFarland, E., W. 2003
  • Synthesis of tungsten oxide on copper surfaces by electroless deposition Chemistry of Materials Baeck, S., H., Jaramillo, T., F., Stucky, G., D., McFarland, E., W. 2003; 15 (18): 3411-3413
  • Enhancement of photocatalytic and electrochromic properties of electrochemically fabricated mesoporous WO3 thin films Advanced Materials Baeck, S., H., Choi, K., S., Jaramillo, T., F., Stucky, G., D., McFarland, E., W. 2003; 15 (15): 1269-1273
  • Combinatorial electrochemical synthesis and characterization of tungsten-based mixed-metal oxides JOURNAL OF COMBINATORIAL CHEMISTRY Baeck, S. H., Jaramillo, T. F., Brandli, C., McFarland, E. W. 2002; 4 (6): 563-568

    Abstract

    Automated systems for electrochemical synthesis and high-throughput screening of photoelectrochemical materials were developed and used to prepare tungsten-based mixed-metal oxides, W(n)O(m)M(x) [M = Ni, Co, Cu, Zn, Pt, Ru, Rh, Pd, and Ag], specifically for hydrogen production by photoelectrolysis of water. Two-dimensional arrays (libraries) of diverse metal oxides were synthesized by automated cathodic electrodeposition of the oxides on Ti foil substrates. Electrolytes for the mixed oxides were prepared from various metal salts added to a solution containing tungsten stabilized as a peroxo complex. Electrodeposition of the peroxo-stabilized cations gave rise to three distinguishable oxide groups: (1) mixed-metal oxides [Ni], (2) metal-doped tungsten oxides [Pt, Ru, Rh, Pd, Ag], and (3) metal-metal oxide composites [Co, Cu, Zn]. The oxides typically showed n-type semiconducting behavior. Automated measurement of photocurrent using a scanning photoelectrochemical cell showed the W-Ni mixed oxide had the largest relative zero bias photocurrent, particularly at a low Ni concentration (5-10 atomic percent Ni). Pt and Ru were also found to increase the photoactivity of bulk tungsten oxide at relatively low concentrations; however, at concentrations above 5 atomic percent, crystallization of WO(3) was inhibited and photoactivity was diminished. Addition of Co, Cu, and Zn to WO(3) was not found to improve the photoelectrochemical activity.

    View details for DOI 10.1021/cc020014w

    View details for Web of Science ID 000179254700006

    View details for PubMedID 12425600

  • Controlled electrodeposition of nanoparticulate tungsten oxide NANO LETTERS Baeck, S. H., Jaramillo, T., Stucky, G. D., McFarland, E. W. 2002; 2 (8): 831-834

    View details for DOI 10.1021/nl025587p

    View details for Web of Science ID 000177485500008

  • Controlled electrodeposition of nanoparticulate tungsten oxide Nano Letters Baeck, S., H., Jaramillo, T., F., Stucky, G., D., McFarland, E. 2002; 2 (8): 831-834
  • High-throughput screening system for catalytic hydrogen-producing materials JOURNAL OF COMBINATORIAL CHEMISTRY Jaramillo, T. F., Ivanovskaya, A., McFarland, E. W. 2002; 4 (1): 17-22

    Abstract

    A high-throughput screening system and methodology were developed for libraries of hydrogen (H(2)) producing catalytic materials. The system is based on the chemo-optical properties of WO(3), which give rise to reflectance changes in the presence of H(2). Pd-coated WO(3) sensors were synthesized and examined for their hydrogen sensitivity, wavelength-dependent reflectance, and performance in the presence of water vapor. For high-throughput screening, a polypropylene reactor block was designed and constructed to house 8 x 12 catalyst libraries deposited as thin films. When the library and reactor block are assembled together, 96 independent microreactor units are formed. A large-area Pd/WO(3) sensor film covers and seals all microreactors, forming a 96-element 2-D H(2) sensor array. As H(2) is produced differentially across the library, the reflectance changes of the Pd/WO(3) film are monitored by reflectivity sensors that scan the surface every 30 s. The time-dependent changes in reflectance indicate relative rates of H(2) production. A library of cathode electrocatalysts was synthesized from Ti, Pt, Ni, Au, Pd, Al, Ag, Ge, and mixtures thereof to demonstrate the H(2) high-throughput screening system. The results of the electrolytic screening are in agreement with expected literature trends: mixtures of Ni and samples containing Pt and Pd generated H(2) at the greatest rates, while Ge- and Ti-based materials were the least effective electrocatalysts. A mixture of 80% Al and 20% Pt was found to have the highest rate of H(2) production. This high-throughput screening system is applicable in a variety of catalytic screening applications where hydrogen is the desired product.

    View details for DOI 10.1021/cc010054k

    View details for Web of Science ID 000174085200002

    View details for PubMedID 11831878

  • Influence of composition and morphology on photo and electrocatalytic activity of electrodeposited Pt/WO3 Baeck, S., H, Jaramillo, T., F., McFarland, E., W. 2002
  • Combinatorial electrochemical synthesis and characterization of tungsten-based mixed metal oxides Journal of Combinatorial Chemistry Baeck, S., H., Jaramillo, T., F., Brändli, C., McFarland, E. 2002; 4 (6): 563-568
  • High-throughput screening system for catalytic hydrogen-producing materials Journal of Combinatorial Chemistry Jaramillo, T., F., Ivanovskaya, A., McFarland, E., W. 2002; 4 (1): 17-22
  • Automated synthesis and characterization of diverse libraries of macroporous alumina ELECTROCHIMICA ACTA Brandli, C., Jaramillo, T. F., Ivanovskaya, A., McFarland, E. W. 2001; 47 (4): 553-557
  • Automated synthesis and characterization of diverse libraries of macroporous alumina Electrochimica Acta Brandli, C., Jaramillo, T., F., Ivanovskaya, A., McFarland, E., W. 2001; 47 (4): 553-557
  • The Investigation of Photoelectrochemical Hydrogen Production Using Combinatorial Chemistry Jaramillo, T., F., Ivanovskaya, A., Brändli, C., McFarland, E., W. 2000