Intramolecular hydrogen bond engineering of covalent organic frameworks accelerates proton transfer for efficient H₂O₂ electrosynthesis

The electrosynthesis of hydrogen peroxide (H₂O₂) presents a sustainable route to replace the energy-intensive anthraquinone (AQ) process, but its efficiency is often limited by sluggish water dissociation and proton transfer kinetics. Herein, we demonstrate a covalent organic framework (COF) featuring adjacent imine and AQ units (1,5-TfpAQ), which uniquely constructs an intramolecular hydrogen-bond (H-bond) between the protonated imine and the carbonyl oxygen of AQ that significantly accelerates proton transfer between the two moieties. The optimal 1,5-TfpAQ achieves a remarkable H₂O₂ production rate of 15.5 mol g⁻¹ h⁻¹ at approximately 120 mA cm⁻² with a Faradaic efficiency (FE) up to 80.0 % in 0.1 M KOH, simultaneously demonstrating exceptional operational stability. Combined experimental and theoretical studies elucidate that the intramolecular H-bond facilitates the formation of a weakly H-bonded water network at electrode surface, thereby promoting water dissociation and enabling rapid proton transfer. The sustained proton supply favors the conversion of AQ into anthrahydroquinone (H₂AQ), and subsequently decreases the energy barrier for the reduction of adsorbed oxygen (*O₂) into *OOH intermediates. This work highlights the strategic construction of an intramolecular H-bond as the effective pathway for proton transfer, and establishes a fundamental design principle for advanced COF electrocatalysts.