Decoding chemical structure–interface correlation in covalent organic framework for sustainable organic electrosynthesis

Covalent Organic Frameworks (COFs) are a promising class of next-generation sustainable catalysts. Their robust backbones and tunable chemical structures offer them unique physicochemical properties. Conjugated COFs also show semiconducting behavior, which makes them suitable for charge and mass transfer processes. These features position COFs as strong candidates for electrocatalysis. However, their electrocatalytic performance is not yet well understood. In particular, there is limited knowledge about their interfacial structure and properties, which hinders their broader application. We herein report conjugated, highly porous COF-electrodes to address these issues, using the oxidation of benzylamine derivatives coupled with parallel cathodic hydrogen production as a model electrocatalytic system. We investigated the structure of the catalyst–medium interface and studied its potential-dependent capacitive and impedance behavior. By tuning the COF's physicochemical structure, we identified operando hydrogen bonding and surface adsorption interactions between the substrates and electrodes, which impacted the overall electrocatalytic performance. This first-of-its-kind, proof-of-concept study establishes the effectiveness of COFs as sustainable electrocatalysts and highlights the role of their physicochemical tuning in controlling the catalytic activities.