Understanding the interaction between transition metal doping and ligand atoms of ZnS and ZnO monolayers to promote the CO reduction reaction.

Single-atom catalysts (SACs) obtained by doping transition metal (TM) atoms into stable monolayers are a promising way to improve the CO reduction reaction (CRR) performance. In this work, we theoretically investigated the effect of ligand atoms around the doped TM (TM = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, and Cu) in ZnO and ZnS for promoting the CRR performance. We found that the ligand atoms around the TM can influence its oxidation state and the electronic properties of the SACs, thus affecting their CRR activity.