Electrocatalysis of hydrogen peroxide reactions on perovskite oxides: experiment versus kinetic modeling

Abstract

Hydrogen peroxide has been identified as a stable intermediate of the electrochemical oxygen reduction reaction on various electrodes including metal, metal oxide and carbon materials. In this article we study the hydrogen peroxide oxidation and reduction reactions in alkaline medium using a rotating disc electrode (RDE) method on oxides of the perovskite family (LaCoO₃, LaMnO₃ and La_0.8Sr_0.2MnO₃) which are considered as promising electrocatalytic materials for the cathode of liquid and solid alkaline fuel cells. The experimental findings, such as the higher activity of Mn-compared to that of Co-perovskites, the shape of RDE curves, and the influence of the H₂O₂ concentration, are rationalized with the help of a microkinetic model.