Nickel-Cobalt Based Electrocatalyst Supported on Copper Foam for Electrooxidation of 5-Hydroxymethylfurfural to 2,5-Furandicarboxylic Acid

Driven by fossil resource depletion and environmental concerns, the conversion of agricultural biomass wastes derived compounds into platform chemicals, such as 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA), has emerged as a key strategy for sustainable chemical production. This study developed nickel-cobalt (Ni-Co) based electrocatalysts supported on copper foam (CF) for the electrooxidation of HMF to FDCA. The obtained Ni-Co based electrodes are referred to as NixCoy/CF, where x and y represent the relative proportions of nickel and cobalt in the electrocatalyst. Among the electrodes tested, the Ni1Co1/CF electrode demonstrated the highest performance, achieving nearly 100 % HMF conversion with both FDCA yield and Faradaic efficiency of approximately 95 % in a dilute KOH electrolyte (0.1 mol L–1 KOH) in an H-type electrolysis cell at an applied potential of 1.515 V vs. the reversible hydrogen electrode for 3 h. The Ni1Co1 electrocatalyst revealed a nanosheet-like morphology, which can provide a larger number of active sites for electrochemical HMF oxidation reaction. Based on X-ray diffraction analysis, the Ni1Co1 electrocatalyst was composed of NiO and Co3O4 with a heterostructure, which enables efficient HMF conversion under mild conditions.