Trend in Oxygen Reduction Reaction on Transition Metal Oxide Surfaces

Abstract

Perovskite transition metal oxides exhibit high electrocatalytic activities for both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER), comparable to the state-of-the-art precious metal/metal oxide catalysts in alkaline environment. To better understand the origin of these oxygen electrocatalytic activities, we survey physical-chemical trends in the perovskites and their relations to the ORR activity, from which we postulate the role of the electronic states in stabilizing the reaction intermediates and facilitating oxygen charge transfer. Our finding supports the role of the electronic states in governing the metal–oxygen bond strength and the degree of mixing between the metal and the oxygen states as the underlying physical-chemical properties that control the activities of the perovskite oxides for oxygen electrocatalysis.