First principles study of oxygen adsorption and dissociation on the Pd/Au surface alloys

The formation of Pd/Au surfaces and their catalytic performance toward oxygen dissociation were investigated using periodic density functional methods. We show that Pd can readily incorporate into the second layer of Au(100) and Au(111) substrates with the assistance of Au vacancies. Pd/Au(100) exhibits better catalytic activity toward oxygen dissociation than Pd/Au(111). Specifically, the sub-layer Pd atoms of Pd/Au(100) can promote the oxygen dissociation and stabilize the surface structure after adsorbing oxygen atoms. On the contrary, the sub-layer Pd atoms of Pd/Au(111) slightly hinder the oxygen dissociation.