From structure to function: MOF-based and COF-based catalysts for efficient electrocatalytic H2O2 production via 2e− ORR

Abstract

The production of H₂O₂ through the two-electron oxygen reduction reaction (2e⁻ ORR) is an innovative method that replaces the traditional anthraquinone process and the direct mixing of hydrogen and oxygen, thus eliminating the disadvantages of high energy consumption and high risk. By utilizing water and renewable electricity, H₂O₂ can be produced safely and in an environmentally friendly manner, achieving on-site production and in situ utilization. Metal–Organic Frameworks (MOFs) and Covalent Organic Frameworks (COFs), as highly ordered porous materials, demonstrate clear structural characteristics and great design flexibility through precise connections of inorganic metal ions and organic ligands via covalent or coordination bonds. These structural features directly relate to their functional performance in electrocatalysis, especially in the 2e⁻ ORR process. By selecting appropriate organic ligands, adjusting atomic coordination environments, choosing optimal complex structures, and preparing highly active catalysts through methods such as pyrolysis, the catalytic performance of MOFs and COFs is greatly enhanced. This review, from structure to function, delves into the innovative applications of MOFs and COFs in 2e⁻ ORR, not only improving the efficiency and selectivity of H₂O₂ production but also contributing to environmental management and sustainable development. Finally, based on current technological and application challenges and opportunities, future research directions and practical applications are proposed.