AgPO electrocatalyst for oxygen reduction reaction: enhancement from positive charge.

We have demonstrated AgPO as an active non-Pt electrocatalyst with enhanced activity compared with Ag for oxygen reduction reaction (ORR). Density functional theory reveals that better ORR performance of Ag atoms on AgPO surface than that on pure silver surface originates from more appropriate oxygen adsorption on positively charged Ag atoms. Further study of the surface geometry of AgPO including tetrahedron, rhombic dodecahedron and cube indicates that the highest density of Ag and appropriate oxygen adsorption on {110} surface of rhombic dodecahedral AgPO lead to the highest ORR activity, which is about 12 times that of Pt catalysts from a commercial perspective. It may be applicable for developing low-cost and highly active non-Pt catalytic materials from a broader range of material systems.