Efficient H₂O₂ Synthesis Through a Two-Electron Oxygen Reduction Reaction by Electrocatalysts

The two-electron oxygen reduction reaction (2e-ORR) for the sustainable synthesis of hydrogen peroxide (H₂O₂) has demonstrated considerable potential for local production of this environmentally friendly chemical oxidant on small, medium, and large scales. This method offers a promising alternative to the energy-intensive anthraquinone approach, placing a primary emphasis on the development of efficient electrocatalysts. Improving the efficiency of electrocatalysts and uncovering their catalytic mechanisms are essential steps in achieving high 2e-ORR activity, selectivity, and stability. This comprehensive review summarizes recent advancements in electrocatalysts for in-situ H₂O₂ production, providing a detailed overview of the field. In particular, the review delves into the design, fabrication, and investigation of catalytic active sites contributing to H₂O₂ selectivity. Additionally, it highlights a range of electrocatalysts including pure metals and alloys, transition metal compounds, single-atom catalysts, and carbon-based catalysts for the 2e-ORR pathway. Finally, the review addresses significant challenges and opportunities for efficient H₂O₂ electrosynthesis, as well as potential future research directions.