Integrating Electrocatalytic 5-Hydroxymethylfurfural Oxidation and Hydrogen Production via Co–P-Derived Electrocatalysts

Abstract

Electrocatalytic biomass valorization with renewable energy input represents a promising way to produce sustainable and nonfossil-based carbon products. Even more desirable is that the oxidative biomass upgrading can be integrated with H 2 production in a single electrolyzer. Herein, we report that electrodeposited Co–P can act as competent electrocatalysts for 5-hydroxymethylfurfural (HMF) oxidation to 2,5-furandicarboxylic acid (FDCA) at the anode and H 2 production at the cathode simultaneously in alkaline media. When serving as a catalyst precursor on the anode, Co–P was able to achieve a current density of 20 mA/cm 2 for HMF oxidation in 1.0 M KOH with 50 mM HMF at 1.38 V vs RHE, prior to the takeoff of the competing reaction, O 2 evolution. Long-term chronoamperometry demonstrated a nearly 100% conversation of HMF and a ∼90% yield of FDCA. When HMF oxidation and H 2 evolution were integrated in one electrolyzer with a Co–P/Co–P catalyst couple, the potential required to achieve a current density of 20 mA/cm 2 was 1.44 V, 150 mV lower than that of overall water splitting. Nearly unity Faradaic efficiency was obtained for H 2 evolution. Overall, our results indicate that it is feasible to employ earth-abundant electrocatalyts to integrate H 2 production and oxidative biomass upgrading with higher energy conversion efficiency than water splitting as well as to produce valuable products at both cathode and anode in a single electrolyzer.