"B" site-modulated perovskite oxide materials for efficient electrochemical water oxidation to hydrogen peroxide

Abstract

Two-electron water oxidation (2e− WOR) has emerged as a promising method for H2O2 synthesis. However, achieving catalyst’ stability for hydrogen peroxide (H2O2) production through 2e− WOR under harsh oxidative conditions remains a significant challenge. Perovskite oxide catalysts have shown potential at low currents, but their electrocatalytic activity diminishes at high current densities. In this study, we successfully fabricated highly efficient 2e− WOR electrocatalysts by carefully selecting suitable B site metals with optimal O* and OH* adsorption characteristics. Our results demonstrate that the LaCoO3 catalyst exhibit exceptional H2O2 production rates, reaching 2977.29 μmol min−1 g−1. Furthermore, the LaCoO3 catalysts demonstrate remarkable durability and stable electrochemical performance even after an ultra-long 120-hour stability test. Density Functional Theory calculations (DFT) further demonstrate that we successfully screened catalysts that are thermodynamically more favorable at a 2e− WOR pathway and accelerate the rate-determining step of OH* to H2O2 by B-site modulation. This work presents a simple and effective strategy for designing perovskite catalysts tailored for efficient 2e− WOR.