Brønsted bases promote interfacial proton transfer for enhanced biomass electrocatalysis

Abstract

Efficient electrooxidation of 5-hydroxymethylfurfural (HMF) is essential for the production of valuable chemicals from biomass. However, the sluggish interfacial proton transfer kinetics during the reaction significantly hinder its progress. This study proposes that the introduction of Brønsted bases on cobalt-based catalysts can enhance HMF oxidation by modulating interfacial proton transfer kinetics. Density functional theory calculations, in situ spectroscopy, and experimental results demonstrate that phosphate (Pi) groups on the cobalt surface shorten the distance between the proton donor and acceptor, effectively promoting interfacial proton transfer during the dehydrogenation of HMF. Consequently, the Pi-functionalized catalyst shows a 6.5-fold increase in current density compared with the unmodified cobalt catalyst and achieves near 100% selectivity for 2,5-furandicarboxylic acid, attaining a current density of 1000 mA cm⁻² at 1.41 V_RHE for efficient HMFOR. This work provides insights into designing efficient catalysts for industrial applications through surface site functionalization.