Electrocatalytic hydrogenation of furfural over copper nitride with enhanced hydrogen spillover performance†

Abstract

The electrochemical reduction of biomass-derived furfural (FF) is an advantageous route to alleviate the consumption of fossil fuels and hydrogen. However, the development of efficient catalytic systems to obtain furfuryl alcohol (FAL) with high selectivity is still challenging. Herein, a copper nitride nanowire catalyst in situ grown on copper foam (Cu₃N Nw/CF) is synthesized, which achieves nearly 100% selectivity for FAL with 94.6% faradaic efficiency (FE) in the electrochemical reduction of FF. Thiol assembly and operando Raman investigations reveal an adsorptive hydrogen (H_ads) dependent electrocatalytic hydrogenation (ECH) pathway for FAL production. Moreover, electrokinetic studies have demonstrated that the FF hydrogenation on Cu₃N Nw/CF follows the Langmuir–Hinshelwood (L–H) mechanism. The much higher activity of Cu₃N Nw/CF than that of copper foam (CF) is due to the promoted H_ads spillover from water dissociation, which then reacts efficiently with FF via the ECH mechanism. Furthermore, density functional theory (DFT) calculations verify that the superior water dissociation ability and the preferable parallel FF adsorption on Cu₃N synergistically enhance the thermodynamics and kinetics of FAL production.