Influence of Atomic-Level Morphology on Catalysis: The Case of Sphere and Rod-Like Gold Nanoclusters for CO2 Electroreduction

Gold-based materials hold promise in electrocatalytic reduction of CO2 to fuels. However, the polydispersity of conventional gold nanostructures limits mechanistic studies. Here, we report two types of atomically precise Au25 nanoclusters (1 nm) with distinct morphology (i.e., nanosphere and nanorod) for CO2 reduction catalysis. The Au25 nanosphere exhibits higher Faradaic efficiency for CO with higher formation rates compared to the Au25 nanorod. First-principles calculations reveal that the negative charge and the energetically favorable removal of one ligand to generate an active site on the nanosphere can better stabilize the important *COOH intermediate in CO2 electroreduction.