Tuning Electrochemical Properties of Metal‐Free Covalent Organic Frameworks Through Hydrogen‐Bonding Interactions

Abstract Accurately identifying and enhancing catalytic activity in metal‐free, carbon‐based electrocatalysts remains a fundamental challenge, largely due to the difficulty of concurrently optimizing hydrophilicity and oxygen affinity at active sites. Herein, a hydrogen‐bonding‐driven strategy is presented to boost oxygen reduction reaction (ORR) performance in covalent organic frameworks (COFs). By integrating hydrazone linkages with alkoxy‐functionalized pore walls, a hydrophilic skeleton capable of forming tunable intramolecular hydrogen‐bonding networks is constructed. These interactions induce asymmetric electron distributions that enhance the simultaneous adsorption of water and oxygen molecules. Consequently, the hydrazone‐linked COFs exhibit a half‐wave potential of 0.78 V, outperforming all previously reported metal‐free COF‐based electrocatalysts. Density functional theory (DFT) calculations reveal that the improved activity originates from favorable * OOH and * OH adsorption energies at hydrogen‐bonding centers, along with stabilized O 2 /H 2 O binding. This synergistic modulation of the local microenvironment—through hydrogen bonding and electronic structure engineering—affords enhanced activity, selectivity, and long‐term durability. This work offers a rational design paradigm for advancing metal‐free COF electrocatalysts toward sustainable energy conversion.