Designing Heterocyclic Covalent Organic Frameworks with Tunable Electronic Structures for Efficient Electrosynthesis...

The electrocatalytic production of hydrogen peroxide (H₂O₂) through the two-electron oxygen reduction reaction (2e^- ORR) has garnered significant research attention in recent years due to its numerous appealing advantages, such as being eco-friendly and exhibiting high energy conversion efficiency. Metal-free carbon materials with specific catalytic sites have been recognized as potential electrocatalysts for 2e^- ORR; however, the design of highly efficient catalysts with well-defined structures and long-term stability for large-scale H₂O₂ production remains unsatisfactory. In this study, three covalent organic frameworks (COFs) - imine-linked LZU-1, oxazole-linked LZU-190, and thiazole-linked LZU-190(S), are successfully synthesized to explore their catalytic activity in electrocatalytic H₂O₂ production. Among these, the carbon sites LZU-190(S) are predominantly activated by the introduced adjacent heteroatoms via electronic effects, resulting in much higher H₂O₂ selectivity compared to the oxazole and imine linkages. This work provides new insights into developing COFs-based electrocatalysts for efficient H₂O₂ generation.