Tailoring Reactant Adsorption Configuration with a Built-in Electric Field for Enhanced Electrochemical Synthesis

Electrochemical synthesis offers a promising pathway for upgrading biomass. Herein, we report a Cu(OH)2–CoOOH heterojunction electrocatalyst with an interfacial built-in electric field (BEF) that tailors the adsorption configuration of 5-hydroxymethylfurfural (HMF) electrooxidation (HMFOR). Systematic characterization reveals that the BEF induces Co 3d orbital splitting, stabilizing the parallel adsorption configuration of the reactants via enhanced π-conjugation. This optimized adsorption configuration facilitates rapid HMF activation and efficient intermediate conversion. Consequently, the heterojunction electrocatalyst achieves a current density of 600 mA cm–2 at 1.45 V vs RHE, with over 99% HMF conversion, 2,5-furandicarboxylic acid (FDCA) yield, and Faradaic efficiency. The synergy between adsorption configuration control and interfacial charge transfer kinetics enables this superior performance. This work highlights the critical role of the BEF in modulating adsorption configurations, offering a promising strategy for designing efficient electrocatalysts for biomass upgrading.