Rational design of edges of covalent organic networks for catalyzing hydrogen peroxide production

Electrochemical synthesis of hydrogen peroxide is significant in energy systems, and many efforts have been made to develop highly selective and active carbon-based catalysts. However, it is still a challenge to control the local and density of active sites in carbons precisely. Herein, we demonstrate a novel tactic to construct catalysts with controllable density and location of active sites and well-defined active ability by edge-defect engineering of covalent organic networks (CONs). The optimized catalyst with dangling carbonyl group displays notable activity in catalyzing oxygen reduction reaction with a 2e– pathway, and a selectivity of above 99 %, with a faradaic efficiency of 93 %. Density functional theory calculations further reveal that the carbons next to carbonyl group on the edges enhance the binding ability of OOH*, which contributes to the high activity and selectivity. This work provides a general insight of designing H2O2 electrosynthesis catalysts through regulating the edge-defective properties of CONs.