Design Strategies of Non-Noble Metal-Based Electrocatalysts for Two-Electron Oxygen Reduction to Hydrogen Peroxide.

Abstract

Hydrogen peroxide (H2 O2 ) is a highly value-added and environmentally friendly chemical with various applications. The production of H2 O2 by electrocatalytic 2e- oxygen reduction reaction (ORR) has drawn considerable research attention, with a view to replacing the currently established anthraquinone process. Electrocatalysts with low cost, high activity, high selectivity, and superior stability are in high demand to realize precise control over electrochemical H2 O2 synthesis by 2e- ORR and the feasible commercialization of this system. This Review introduces a comprehensive overview of non-noble metal-based catalysts for electrochemical oxygen reduction to afford H2 O2 , providing an insight into catalyst design and corresponding reaction mechanisms. It starts with an in-depth discussion on the origins of 2e- /4e- selectivity towards ORR for catalysts. Recent advances in design strategies for non-noble metal-based catalysts, including carbon nanomaterials and transition metal-based materials, for electrochemical oxygen reduction to H2 O2 are then discussed, with an emphasis on the effects of electronic structure, nanostructure, and surface properties on catalytic performance. Finally, future challenges and opportunities are proposed for the further development of H2 O2 electrogeneration through 2e- ORR, from the standpoints of mechanistic studies and practical application.