Recent Advances on the Electrosynthesis of H2O2 Through Two-Electron Water Oxidation.

Hydrogen peroxide (H₂O₂) is an eco-friendly oxidant with broad industrial applications, including wastewater treatment and paper bleaching. Despite the energy-intensive anthraquinone process is the dominant method for H₂O₂ production, there is a growing interest in direct electrochemical synthesis as a greener production method. Electrochemical synthesis, leveraging renewable energy and abundant resources, offers a promising alternative for on-site H₂O₂ production. This review focuses on advancements in the two-electron water oxidation reaction (2e^- WOR) for H₂O₂ synthesis, covering the reaction mechanisms, catalyst development, and reactor designs. In particular, this review emphasizes the importance of understanding reaction mechanisms on guiding the electrocatalyst design. At the same time, this review highlights challenges in indirect H₂O₂ through tuning the electrolyte ions, like the carbonate or bicarbonate electrolytes, and the need for a comprehensive understanding of the electrolyte ion mediation pathways to guide the development of accurate theoretical models for predicting catalyst performance.