Tuning electronic structure of Ni₃S₂ with tungsten doping for high-performance electrooxidation of 5-hydroxymethylfurfural

Electrooxidation of the biomass derivative 5-hydroxymethylfurfural (HMF) is a highly promising approach for attaining versatile value-added chemicals (e.g., 2,5-furandicarboxylic acid, FDCA). Ni-based sulfides are promising electrocatalysts for HMF electrooxidation reaction (HMFOR). However, the HMFOR activity of Ni-based catalysts is far from satisfactory due to the unfavorable adsorption of HMF and OH*. Herein, we propose controlled W doping to effectively modify the electronic configuration of nanostructured Ni3S2 to manipulate adsorption of HMF and OH*, for efficiently converting HMF into FDCA. Experimental and theoretical calculations indicate the incorporation of high-valence W results in the upshift of d-band center of Ni3S2, which facilitates the adsorption and dissociation of water to produce more OH*. Meanwhile, the high-valence W has strong electron-withdrawing ability and attracts electrons from Ni, leading to the elevated Ni valence, which is beneficial to optimizing the adsorption energy of HMF. Both concurrently contribute to the superb HMFOR performance. As a result, W-20-Ni3S2@NF with optimal W dopant exhibits a low driving potential (1.34 V vs. RHE at 10 mA cm(-2)), accompanying with the 100% HMF conversion, 99.2% FDCA selectivity, and 97.3% Faraday efficiency. This work provides a design principle for HMFOR electrocatalysts by modulating the adsorption behaviors of HMF and OH* via rational electronic structure engineering.