(561c) Mechanistic Studies of Fe Based LDH and Phosphosulfides for Oer and HER Using in Situ operando synchrotron X-Ray Spectroscopy and Scattering (Invited)

Transition metal-based, e.g., iron (Fe), oxides and phosphosulfides represent emerging categories of earth-abundant electrocatalyst materials that show superior catalytic activity for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Although a lot of theoretical calculations or hypothesis have proposed that Fe at high oxidation state could be responsible for such high activity, there is few direct experimental evidences to support it. In particular, the catalytic reaction centers of such catalysts are not well identified. In this talk, I will discuss our recent studies on several Fe-based layered double hydroxides for OER and iron phosphosulfides for HER using in situsynchrotron X-ray spectroscopy and scattering to reveal the reaction mechanism. Density function theory is also implemented to better evaluate the reaction pathways and processes. The hope is to provide more experimental, especially in situ operando, evidences to mechanistically understand the fundamental reactions in electrolyzers and fuel cells, thus offering rational strategies for the design of cost-effective and efficient catalysts.