Preparation of Sulfur-Modulated Nickel/Carbon Composites from Lignosulfonate for the Electrocatalytic Oxidation of 5-Hydroxymethylfurfural to 2,5-Furandicarboxylic Acid

Electrochemical oxidation of biomass-derived 5-hydroxymethylfurfural (HMF) is a promising way to produce 2,5-furandicarboxylic acid (FDCA). Here, a flowerlike hybrid composed of sulfur-modulated metallic nickel nanoparticles coupled with carbon frameworks (S–Ni@C) is synthesized via two steps, achieving high selectivity and efficiency for HMF oxidation. Lignosulfonate, which is pulp waste, is used as a carbon and sulfur precursor. The optimized S–Ni@C electrode exhibits a nearly 100% conversion of HMF, 96% yield of FDCA, and 96% high faradaic efficiency. This work provides insights into the design and synthesis of electrocatalysts for biomass upgrading.