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

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 similar to 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.