Max Kessler

All Publications

• The Efficiencies and Products of Dilute Methane Oxidation in a Chlorine Radical Photoreactor. Environmental science & technology Randall, R., Kessler, M. I., Jackson, R. B., Majumdar, A. 2026

  Abstract

  A potential approach for mitigating the climate impact of hard-to-abate, dilute (less than 1000 ppm; ppm) methane (CH4) is gas-phase advanced oxidation (GPAO). Here, we present experimental results from a benchtop GPAO reactor oxidizing CH4 with chlorine radicals (Cl·) produced from the photolysis of chlorine gas (Cl2), a process we term "Cl2-GPAO." We find that at CH4 concentrations from 2 to 90 ppm, supplying Cl2 in a ratio of 1:1 with CH4 uses photogenerated Cl· efficiently, with 3 Cl· photogenerated for each CH4 oxidized with only 20% of Cl· recombining to Cl2. When more Cl2 is added, the product balance shifts from mainly carbon monoxide to mainly carbon dioxide. Cl2-GPAO performs similarly under relative humidities between 5 and 60%. In the presence of ppm-level ammonia, toluene, nitric oxide, and hydrogen sulfide, CH4 conversion decreases, suggesting that gaseous contaminants compete with CH4 for Cl·. Gas chromatography-mass spectrometry revealed that Cl2-GPAO with 30 ppm CH4 and Cl2 produces 1.05 ± 0.32 part per billion (ppb) methyl chloride and 1.25 ± 0.38 ppb chloroform. Methylene chloride and carbon tetrachloride were not detected. We discuss the implications for cost-effective and climate-beneficial Cl2-GPAO at scale.

  View details for DOI 10.1021/acs.est.6c04737

  View details for PubMedID 42400516

• A Humidity-Tolerant Photocatalyst for Methane Removal. Environmental science & technology Kessler, M. I., Randall, R., Wan, G., Xu, K., Zhang, Y., Dionne, J. A., Jackson, R. B., Majumdar, A. 2026

  Abstract

  To mitigate the climate impacts of methane, there has been substantial interest in the complete oxidation of methane to carbon dioxide by using photocatalysis at ambient temperatures. However, previous studies have primarily examined methane concentrations well above those found at most emission sources and have overlooked the role of realistic humidity. This work reports methane oxidation rates at 25 °C for oxide-based photocatalysts for methane concentrations ranging from 2 to 5000 ppm. Even under dry conditions with less than 2% relative humidity, residual water attracted to the hydrophilic surfaces of these photocatalysts severely inhibits methane oxidation. Thinning this water layer boosts methane oxidation rates by up to 1 order of magnitude. Furthermore, surface modification of titanium dioxide with a hydrophobic fluorosilane coating (1H,1H,2H,2H-perfluorooctyltriethoxysilane) enables room temperature photocatalytic removal of dilute methane even under conditions with up to 80% relative humidity. These findings and engineering solutions offer guidance for the development of light-driven approaches for scalable methane removal.

  View details for DOI 10.1021/acs.est.5c16764

  View details for PubMedID 41665929

• Temperature responses from methane mitigation approaches vary widely due to non-methane impacts ENVIRONMENTAL RESEARCH LETTERS Abernethy, S., Buechler, R., Kessler, M., Jackson, R. B. 2024; 19 (8)

  View details for DOI 10.1088/1748-9326/ad60e0

  View details for Web of Science ID 001280725800001

• A semi-continuous process for co-production of CO2-free hydrogen and carbon nanotubes via methane pyrolysis CELL REPORTS PHYSICAL SCIENCE Sun, E., Zhai, S., Kim, D., Gigantino, M., Haribal, V., Dewey, O. S., Williams, S. M., Wan, G., Nelson, A., Marin-Quiros, S., Martis, J., Zhou, C., Oh, J., Randall, R., Kessler, M., Kong, D., Rojas, J., Tong, A., Xu, X., Huff, C., Pasquali, M., Gupta, R., Cargnello, M., Majumdar, A. 2023; 4 (4)

  View details for DOI 10.1016/j.xcrp.2023.101338

  View details for Web of Science ID 001000123600001

• Assessing the potential benefits of methane oxidation technologies using a concentration-based framework ENVIRONMENTAL RESEARCH LETTERS Abernethy, S., Kessler, M. I., Jackson, R. B. 2023; 18 (094064)

  View details for DOI 10.1088/1748-9326/acf603

• On the production of ancient Egyptian blue: Multi-modal characterization and micron-scale luminescence mapping PLOS ONE Seymour, L. M., Nicola, M., Kessler, M. I., Yost, C. L., Bazzacco, A., Marello, A., Ferraris, E., Gobetto, R., Masic, A. 2020; 15 (11): e0242549

  Abstract

  The ancient pigment Egyptian blue has long been studied for its historical significance; however, recent work has shown that its unique visible induced luminescent property can be used both to identify the pigment and to inspire new materials with this characteristic. In this study, a multi-modal characterization approach is used to explore variations in ancient production of Egyptian blue from shabti statuettes found in the village of Deir el-Medina in Egypt (Luxor, West Bank) dating back to the New Kingdom (18th-20th Dynasties; about 1550-1077 BCE). Using quantitative SEM-EDS analysis, we identify two possible production groups of the Egyptian blue and demonstrate the presence of multiple phases within samples using cluster analysis and ternary diagram representations. Using both macro-scale non-invasive (X-rays fluorescence and multi-spectral imaging) and micro-sampling (SEM-EDS and Raman confocal microspectroscopy) techniques, we correlate photoluminescence and chemical composition of the ancient samples. We introduce Raman spectroscopic imaging as a means to capture simultaneously visible-induced luminesce and crystal structure and utilize it to identify two classes of luminescing and non-luminescing silicate phases in the pigment that may be connected to production technologies. The results presented here provide a new framework through which Egyptian blue can be studied and inform the design of new materials based on its luminescent property.

  View details for DOI 10.1371/journal.pone.0242549

  View details for Web of Science ID 000595863100047

  View details for PubMedID 33232351

  View details for PubMedCentralID PMC7685487