Electrochemical oxygen reduction for H2O2 production: catalysts, pH effects and mechanisms

Abstract

Electrochemical oxygen reduction offers an efficient and environmentally friendly route for hydrogen peroxide (H₂O₂) generation. This electrochemical process can produce H₂O₂ on-site under ambient conditions. High selectivity and activity two-electron oxygen reduction reaction (2e⁻ ORR) catalysts are crucial for efficient electrochemical H₂O₂ synthesis. Here, metal/metal oxide, carbon material, and single-atom based 2e⁻ ORR catalysts developed to produce H₂O₂ are reviewed. As the performance of the catalysts strongly depends on the pH values of electrolytes, pH effects and reaction mechanisms for the catalysts are further summarized to give a deep insight into this research area. This review would help us better understand the catalysts for electrochemical H₂O₂ synthesis and their rational design in the future.