Electrochemical Synthesis of H2O2 by Two-Electron Water Oxidation Reaction

Hydrogen peroxide (H2O2) is a high-value green chemical oxidant widely used for industrial bleaching, chemical synthesis, and disinfection. Industrially, H2O2 is produced through the energy-intensive anthraquinone process and distributed to the point of use. There is a growing interest in electrochemically producing H2O2 onsite to mitigate transportation cost and safety concerns and leveraging renewable electricity. Most research has been dedicated to the two-electron oxygen reduction to produce H2O2. For the past decade, growing attention has been paid to the two-electron water oxidation reaction (2e-WOR) to produce H2O2. This review focuses on the research progress on 2e-WOR, including basic principles, catalyst development, and H2O2 detection. Computational approaches to study candidate materials for 2e-WOR are detailed, and various experimental reports on catalysts are summarized. Ulterior electrochemical factors that impact H2O2 production are discussed, along with device-level design. Finally, a holistic perspective on water oxidation reaction is offered, and open questions for future work are presented.