Recent Progress of Electrochemical Production of Hydrogen Peroxide by Two‐Electron Oxygen Reduction Reaction

Abstract

Shifting electrochemical oxygen reduction reaction (ORR) via two‐electron pathway becomes increasingly crucial as an alternative/green method for hydrogen peroxide (H ₂O ₂) generation. Here, the development of 2e ⁻ ORR catalysts in recent years is reviewed, in aspects of reaction mechanism exploration, types of high‐performance catalysts, factors to influence catalytic performance, and potential applications of 2e ⁻ ORR. Based on the previous theoretical and experimental studies, the underlying 2e ⁻ ORR catalytic mechanism is firstly unveiled, in aspect of reaction pathway, thermodynamic free energy diagram, limiting potential, and volcano plots. Then, various types of efficient catalysts for producing H ₂O ₂ via 2e ⁻ ORR pathway are summarized. Additionally, the catalytic active sites and factors to influence catalysts’ performance, such as electronic structure, carbon defect, functional groups (O, N, B, S, F etc.), synergistic effect, and others (pH, pore structure, steric hindrance effect, etc.) are discussed. The H ₂O ₂ electrogeneration via 2e ⁻ ORR also has various potential applications in wastewater treatment, disinfection, organics degradation, and energy storage. Finally, potential future directions and prospects in 2e ⁻ ORR catalysts for electrochemically producing H ₂O ₂ are examined. These insights may help develop highly active/selective 2e ⁻ ORR catalysts and shape the potential application of this electrochemical H ₂O ₂ producing method.

Abstract

Electrochemical oxygen reduction reaction (ORR) via 2e ⁻ pathway becomes increasingly crucial for hydrogen peroxide (H ₂O ₂) generation. This work comprehensively reviews the recent works of 2e ⁻ ORR catalysts, in aspects of catalytic mechanism, types of catalysts, factors to influence catalytic performance and potential applications. Additionally, potential strategies are given for developing high‐performance 2e ⁻ ORR catalysts and on‐site applications.