Theoretical study of the mechanism of CO2 reduction catalyzed by a NiFe complex on graphite

This project aimed at understanding the outstanding catalytic behaviour in CO2 electroreduction of a recently synthesized bioinorganic [NiFe] complex inspired by hydrogenase, thanks to computational methods rooted in Density Functional Theory (DFT). The detailed mechanistic insights obtained here explain the high selectivity of the reduction process yielding CH4 as the sole final product, owing to the cooperativity of the two metal atoms. The findings also highlight the role of the ligand sulfur atoms in binding CO2, as well as the influence of the graphite support experimentally used to enhance electron transfers. Additionally, the modelling disclosed details on the competing H2 evolution reaction and the mechanism of proton relay via a modified [NiFe] complex to improve H2 production.