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 Au-25 nanoclusters (1 nm) with distinct morphology (i.e., nanosphere and nanorod) for CO2 reduction catalysis. The Au-25 nanosphere exhibits higher Faradaic efficiency for CO with higher formation rates compared to the Au-25 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.