The adsorption, diffusion and dissociation of O2 on Pt-skin Pt3Ni(1Â 1Â 1): A density functional theory study

► The adsorption of O2 is less stable and the adsorbed O2 gets fewer electrons on the Pt3Ni(1 1 1) surface as compared with that on Pt(1 1 1). ► The diffusion and dissociation of O2 on Pt3Ni(1 1 1) surface become more difficult. ► Possible mechanisms for the enhanced ORR of the Pt3Ni catalyst are proposed.