Lundi 6 mars 2023 à 11h, Amphi H. Daniel (Bât 670, H. Moissan)
Dr. Matthew T. MAYER, Helmholtz Zentrum Berlin for Materials and Energy, Germany
"Electrocatalytic conversion of carbon dioxide – understanding dynamic behaviors of catalysts and cells using in situ methods"
Electrochemical CO2 reduction is a complicated process, with numerous possible reaction pathways that are influenced by many factors which affect the catalyst material and the interfacial chemical environment. Further complicating things, these factors are dynamic during operation, making in situ studies crucial for understanding what is really going on, with the goal of better controlling reaction selectivity. I will summarize our research with three examples: 1) Bimetal catalysts exhibit synergetic effects in product selectivity, but tend to transform drastically under operation, so we study them closely using X-ray absorption and photoelectron spectroscopy techniques to uncover their true active structures. 2) The performance of zero-gap GDE cells are highly sensitive to the electrolyte used at the anode, despite the absence of catholyte. We investigate the cause and effects of unintended cation crossover on the selectivity of Cu. 3) Pulsed potential conditions drastically alter CO2 reduction reaction pathways, and we use time-resolved electrochemical mass spectrometry to observe transient product evolution behaviors.
Dr. Matthew T. Mayer is a group leader at the Helmholtz Zentrum Berlin for Materials and Energy (HZB, Germany) where he focuses on developing catalysts and in situ methods to study interfacial phenomena in electrochemical and photoelectrochemical conversion of CO2 and CO. He earned his B.S. in chemistry from Boise State University (USA), then conducted his doctoral studies at Boston College (USA) before going to EPFL (Switzerland) to work as postdoctoral scientist.