▎ 摘　　要

The development of bifunctional oxygen electrode electrocatalysis for both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) plays a vital role in the solution of the energy crisis as well as the environmental pollution. The purpose of this paper is to investigate the potential of graphene-supported lanthanum oxide clusters (La2O3-Gra) as a bifunctional electrocatalyst; the results show that the optimal catalytic site (up-down1) of the most stable configuration (O-Gra-1) modified by OH group shows outstanding bifunctional catalytic activity with eta ORR of 0.51 V and eta OER of 0.52 V, which can be compared to the commercial Pt-based ORR catalysts and the Ru/Ir-oxides OER catalysts. Furthermore, there is a strong scale-dependent relationship between the adsorption free energy (Delta Gads) of reaction intermediates, resulting in volcano plots between the catalytic activity and Delta Gads, which provides a valuable description for future performance prediction of structurally similar catalysts.