CO oxidation by co-adsorbed atomic O on the Au(321) surface with Ag impurities: A mechanistic study from first-principles calculations

► Au(321) is a representative model for rough Au surfaces. ► We investigated theoretically reaction routes between co-adsorbed CO and O. ► Vicinal complexes react most easily with barriers 0.05-0.3 eV. ► Geminal structures first isomerize to vicinal ones. ► Ag impurities generally do not lower the barrier for CO2 formation.