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.

中文翻译：

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用于生产H2O2的电化学氧气还原：催化剂，pH值影响和机理

电化学减氧为过氧化氢（H ₂ O ₂）的产生提供了一种有效且环保的途径。该电化学过程可以在环境条件下现场产生H ₂ O ₂。高选择性和活性的双电子氧还原反应（2e ^- ORR）催化剂对于高效电化学合成H ₂ O ₂至关重要。在此，开发了金属/金属氧化物，碳材料和单原子基2e ^- ORR催化剂以生产H ₂ O ₂被审查。由于催化剂的性能在很大程度上取决于电解质的pH值，因此将进一步总结催化剂的pH效应和反应机理，以便对该领域进行深入的了解。这项审查将帮助我们更好地了解电化学H ₂ O ₂合成催化剂及其未来的合理设计。