Density functional theory calculations are carried out to identify various configurations of oxygen molecules adsorbed on the Au-doped RuO2 (110) surface.The binding energy calculations indicate that O2 molecules are chemically adsorbed on the coordinatively unsaturated Ru (Rucus) sites and the bridge oxygen vacancies on the Au sites.Transition state calculations show that O* can exist on the Rucus site by O*2 dissociation and diffusion.The calculations of the reaction path of CO indicate that the reaction energy barrier of CO adsorbed on Au with lattice oxygen decreases to 0.28 eV and requires less energy than that on the undoped structure.