CO2 electroreduction on single atom catalysts: Role of the local coordination

Single Atom Catalysts (SACs) are a new frontier in catalysis, merging the positive aspects of both homogeneous and heterogenous catalysts. CO2 electrochemical reduction is a key reaction for the energy transition. In this work, we investigate the role of the local coordination on the activation of CO2 on SACs, by means of density functional theory (DFT) calculations. We scrutinize 20 transitional metal atoms embedded in a graphene support. The results indicate that the local coordination has a critical role both to the binding energy of the metal to the support and the activation of CO2. The role of the environment around the active site is as important as the nature of the metal atom. At the same time, the stability of reaction intermediates strongly depends on the local coordination. In some cases, the relative stability of the intermediates changes as function of the environment, affecting the selectivity of the reaction. This study provides evidence of the importance of the local coordination in single-atom catalysis, a crucial aspect if one is interested in providing a rationale to the reactivity, or in predicting novel catalysts.