Potential induced changes on FeNC and NiNC main active site during CO2RR conditions

MNC catalysts show high activity and selectivity for the CO2 reduction reaction (CO2RR), and are thus promising substitutes for currently used catalysts. Their selectivity depends on the applied potential and while for M = Fe, Ni the formation of CO is most relevant, in the case of Fe the hydrogen evolution reaction (HER) prevails in the potential regime that is of interest for industrial application. Based on previous results we assume that disintegration of Fe from the FeN4 moiety is at the origin of this selectivity change. NiNC shows a more stable production of CO and based on post-mortem analysis less transformation into the metallic state. With this beamtime we will explore the structural changes of Fe/Ni sites by in situ and operando XAS and XES. The aim is to identify which species contribute to the selectivity of which product (CO, H2 or CH4), how they correlate with the induced by potential and whether the gas environment plays a major role.