The Pivotal Role of Carbonates in Electrocatalytic Water Oxidation for Hydrogen Peroxide Production: Performance, Mechanisms, and Future Perspectives

Abstract

ABSTRACT Electrochemical water oxidation for H 2 O 2 synthesis is an environmentally friendly, sustainable production process that generates H 2 O 2 directly from water. This approach shows promise in overcoming the energy consumption and transportation limitations of traditional anthraquinone‐based methods. However, the process is thermodynamically less favorable than the oxygen evolution reaction. Current research primarily focuses on developing highly active and selective anode catalysts through strategies such as doping, defect engineering, and interfacial modifications. Often overlooked in this study is the role of electrolytes. Recent studies indicate that carbonates in 2e − water oxidation reaction function not only as buffers or proton carriers, but also as key reaction participants that significantly influence H 2 O 2 production pathways and efficiency. Nevertheless, a comprehensive summary of their regulatory mechanisms is lacking. Against this backdrop, this paper provides a systematic review of the progress of research on 2e − WOR‐mediated H 2 O 2 synthesis in carbonate media. The paper summarizes the performance of different electrode materials in this system and focuses on the detailed mechanisms of H 2 O 2 synthesis under various electrode materials, including metal oxide, carbon, and porphyrin electrodes. Several studies suggest that carbonates redirect the reaction pathway from 4e − oxygen evolution to 2e − H 2 O 2 production by forming CO 3 2− and percarbonate intermediates (C 2 O 6 2− and HCO 4 − ). This significantly enhances H 2 O 2 selectivity. The paper also summarizes the effects of CO 3 2− /HCO 3 − adsorption energies, cation effects, and flow reactor design on H 2 O 2 synthesis. Finally, the paper identifies key challenges and future opportunities in this field, emphasizing the need to combine in situ characterization and theoretical calculations to deeply reveal reaction mechanisms and identify key intermediates. This approach will provide the theoretical foundation for designing high‐performance catalysts and reactors, ultimately advancing the industrial application of electrolytic H 2 O 2 synthesis technology.

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