Jake Heinlein

All Publications

• The ever-evolving active site: transformation of single atoms to extended structures during the Rh-catalyzed reverse water-gas shift reaction. Faraday discussions Barber, G., Chen, X., Khan, A., Heinlein, J., Gericke, S. M., Li, M., Zakharov, D., Yang, J., Head, A. R., Cargnello, M., Rioux, R. M., Bare, S. R. 2026

  Abstract

  At low temperatures (<400 °C), single atoms of Rh supported on rutile TiO2 (rTiO2) are responsible for the formation of CO during the reverse water gas shift (RWGS), while methane production is associated with the Rh-TiO2 interface due to the observed correlation between methane formation rates and the volume-averaged Rh nanoparticle diameter. As the temperature is increased to >540 °C, there is a notable increase in CO selectivity as the methane production rates tend towards zero. The time to reach zero depends on the temperature but is independent of the initial Rh structure (single atoms and/or nanoparticles), which is controlled by the catalyst preparation method (wetness impregnation versus colloidal nanoparticles). At 600 °C and >4 h time on stream, the catalytic behaviour becomes completely agnostic to the initial Rh structure as well as weight loading, and the catalysts are highly selective for the RWGS reaction. Post-reaction HR-TEM image analysis confirms Rh nanoparticles crystallize/order during the reaction; at 400 °C, most of the Rh particles are disordered, while at 600 °C, they are more ordered (i.e., there is the development of defined faceting). Infrared spectroscopy of CO adsorption on Rh nanoparticles confirms the appearance of defined facets after annealing in nitrogen at high temperatures. Annealing the Rh/rTiO2 catalysts prior to the RWGS reaction demonstrates the structural transformation of Rh depends only on time and temperature and not on reactant or product fugacity. Sites responsible for stabilizing Rh single atoms are no longer competent at higher temperatures, enabling single atom integration into existent nanoparticles. As the reaction temperature is increased to temperatures >540 °C, the dominant Rh structure for CO production evolves from single atoms to extended surfaces.

  View details for DOI 10.1039/d5fd00172b

  View details for PubMedID 42065528

• Linear Scaling Relationships between Relative Diffraction Peak Intensity and Catalytic Oxidation of Light Alkanes ACS CATALYSIS Gao, Y., Bao, M., Zhao, C., Heinlein, J., Li, Z., Zhu, B., Cao, X., Hua, C., He, Y. 2025

  View details for DOI 10.1021/acscatal.5c07646

  View details for Web of Science ID 001629396100001

• Engineering Direct S-Scheme Heterojunctions with Ultrafast Interfacial Charge Transfer: A Case Study on 2-Dimensional α-Fe₂O₃/Cu₂O Interfaces ACS APPLIED MATERIALS & INTERFACES Heinlein, J., He, Y., Song, Y., Zhao, T., Feng, Y., Yanagi, R., Paudel, Y., Sfeir, M. Y., Kocoj, C., Guo, P., Hu, S., Pfefferle, L. 2025

  Abstract

  Longer wavelengths of light contain less energy but comprise more of the solar spectrum, making them important to incorporate into any process aiming for high efficiency. Here, we developed a novel redox-mediated synthetic mechanism to construct a heterojunction with strongly coupled interfaces. Specifically, an α-Fe2O3/Cu2O/CuO nanosheet composite was synthesized, forming an S-scheme α-Fe2O3/Cu2O electronic interface, a burgeoning class of materials designed to upconvert longer wavelengths of light and utilize solar energy more effectively. Through a series of experiments including X-ray photoelectron spectroscopy (XPS), ultraviolet-visible (UV-Vis) diffuse reflectance spectroscopy (UV-Vis-DRS), electrochemical impedance spectroscopy (EIS), and photocatalytic measurements, we were able to fully confirm the electronic structure of the α-Fe2O3/Cu2O interfacial heterojunction. These characterizations demonstrate the S-scheme flow of electrons, which is further supported by COMSOL numerical simulations. The successful formation of the S-scheme heterojunction is made possible through the direct Fe-O-Cu covalent bonding at the interface. These bonds provide ultrafast interfacial charge transfer pathways on picosecond time scales followed by long-lived charge-separated states, as quantified by our transient optical experiments. The proposed redox-mediated synthetic strategy provides a valuable guideline for constructing effective solid heterojunctions with strongly coupled interfaces, which are desirable for various applications in catalysis, energy storage, electronics, photovoltaics, and beyond.

  View details for DOI 10.1021/acsami.5c12210

  View details for Web of Science ID 001586004400001

  View details for PubMedID 41037667

• Strategic preparation of porous magnetic molecularly imprinted polymers via a simple and green method for high-performance adsorption and removal of meropenem TALANTA Ma, X., Wang, Y., Wang, W., Heinlein, J., Pfefferle, L. D., Tian, X. 2023; 258: 124419

  Abstract

  In this study, a facile method has been developed to synthesize a novel type of porous magnetic molecularly imprinted polymers (Fe3O4-MER-MMIPs) for the selective adsorption and removal of meropenem. The Fe3O4-MER-MMIPs, with abundant functional groups and sufficient magnetism for easy separation, are prepared in aqueous solutions. The porous carriers reduce the overall mass of the MMIPs, greatly improving their adsorption capacity per unit mass and optimizing the overall value of the adsorbents. The green preparation conditions, adsorption performance, and physical and chemical properties of Fe3O4-MER-MMIPs have been carefully studied. The developed submicron materials exhibit a homogeneous morphology, satisfactory superparamagnetism (60 emu g-1), large adsorption capacity (11.49 mg g-1), quick adsorption kinetics (40 min), and good practical implementation in human serum and environmental water. Finally, the protocol developed in this work delivers a green and feasible method for synthesizing highly efficient adsorbents for the specific adsorption and removal of other antibiotics as well.

  View details for DOI 10.1016/j.talanta.2023.124419

  View details for Web of Science ID 000955008300001

  View details for PubMedID 36893497