Electrochemical oxygen reduction reaction (ORR) for hydrogen peroxide (H2O2) synthesis offers a sustainable alternative to the anthraquinone process, yet suffers from inherent activity-selectivity tradeoffs. Herein, this work addresses this challenge through the incorporation of Mo into CeO2 (Mo-CeO2) featuring oxygen vacancy-mediated Mo-Ce dual-active sites. Mo incorporation into CeO2 lattice through hydrothermal defect engineering simultaneously elevates oxygen vacancy concentration and induces localized electron redistribution, creating synergistic sites where Mo atoms facilitate proton donation via spontaneous water dissociation while adjacent Ce centers optimize O2 adsorption configurations to enhance the intrinsic activity of H2O2 generation. In-situ characterization and density functional theory calculations reveal that the unique hollow adsorption geometry stabilizes *OOH intermediates and decouples conventional scaling relationships between O2 adsorption and intermediate binding. This atomic-level cooperativity enables an unprecedented H2O2 selectivity of 93%, H2O2 yield of 8.2 mol gcat-1 h-1 at 100 mA cm-2 and exceptional stability. The study establishes an efficient design principle for transition metal oxide catalysts in multi-electron transformations, demonstrating how dual-site engineering can simultaneously enhance intermediate stabilization and reaction kinetics for sustainable electrosynthesis applications.
Gao et al. (Sun,) studied this question.