Density functional theory study of dissociative adsorption of O2 on Pd-skin Pd3Cu(111) surface

The dissociative adsorption of O2 demonstrates a significant correlation with the catalytic efficiency of oxygen reduction catalysts. We have performed density -functional theory calculations to investigate the dissociative adsorption of O2 on the Pd -skin Pd3Cu(1 1 1) surface. The calculated results show that the adsorption configuration denoted as "t-f(h)-b" is energetically favourable on the Pd -skin Pd3Cu(1 1 1) surface. In the context of O2 dissociation, two thermodynamically favourable dissociation pathways have been identified. The first pathway proceeds from the initial state denoted as "t -f -b" to yield two oxygen atoms occupying hcp sites. The second pathway, starting from "t -h -b," leads to the formation of two oxygen atoms positioned at fcc sites. Furthermore, our analysis demonstrates a decrease in the stability of O2 adsorption and a slight increase in the energy barrier for the dissociation of adsorbed O2 compared to the corresponding process on the Pd(1 1 1) surface. This theoretical investigation offers valuable insights that can inform and guide the practical application of Pd -Cu alloy materials as highly effective catalysts for oxygen reduction reaction.