Synergistically enhanced co-adsorption of OH− and HMF on Cu-modified Ni aerogel for biomass upgrading coupled with hydrogen production

The electrochemical oxidation of biomass-derived 5-hydroxymethylfurfural (HMF) represents a promising pathway to synthesize the critical polymer monomer 2,5-furandicarboxylic acid (FDCA). However, the restricted adsorption of both HMF and OH − to the catalyst surface results in low activity and selectivity. To address this issue, this study introduced an electrochemically assisted strategy to synthesize Ni aerogel with Cu heteroatom doping (Ni 0.94 Cu 0.06 /NF), demonstrating excellent performance for HMF to FDCA conversion in alkaline media. The catalyst achieves 10 mA cm −2 at 1.307 V vs. RHE, with outstanding Hydrogen evolution reaction (HER) activity (10 mA cm −2 @11 mV). Notably, the conversion rate of HMF, the selectivity of FDCA and the Faraday efficiency can reach 99.5 %, 99 % and 97 %, respectively. Scanning Electron Microscope (SEM) and transmission electron microscopy (TEM) demonstrated that the aerogel's self-supported 3D framework with interwoven nanowire structure enables efficient exposure of catalytic sites. X-ray photoelectron spectroscopy (XPS) analysis further showed the modification with Cu forms unique Ni O Cu linkage within the catalyst's surface region, which effectively adjusts the electronic configuration of Ni sites and increases lattice oxygen content, thereby enhancing HMF adsorption. Density functional theory (DFT) revealed that the synergistic interplay between Ni and Cu markedly boosts the uptake capacity for both HMF and OH − , improves the rate-determining step (RDS) thermodynamics by reducing its barrier, and consequently accelerates the HMF oxidation reaction (HMFOR). Our findings elucidate fresh perspectives into the structure-performance relationship of nickel-based catalysts and offer a novel approach for designing advanced electrocatalysts for biomass upgrading.