Electrochemical oxidation of 5-hydroxymethylfurfural over a molybdenum sulfide modified nickel-based catalyst

Abstract

Biomass derived small molecules are sustainable feedstocks to synthesize high value-added products. Herein, we demonstrate a facile one-pot hydrothermal method to fabricate a molybdenum sulfide modified nickel-based catalyst for the electrochemical oxidation of HMF to 2,5-furandicarboxylic acid (FDCA). The as-synthesized catalyst shows a unique nano-flower-like microstructure with features of a large surface area, excellent conductivity and high-valence Mo species. Electrochemical tests indicate that the onset potential increases to 1.27 V after the addition of HMF, which is much lower than that of water oxidation. This change suggests that the oxidation of HMF occurs before the slow kinetic oxygen evolution reaction (OER), potentially acting as an alternative to the OER cathodic reaction to drive hydrogen evolution and CO₂ reduction. Moreover, the reaction achieves 100% conversion and 99% selectivity, which is because molybdenum sulfide accelerates the in situ oxidation of Ni²⁺ to NiOOH and Ni³⁺. This study provides a new pathway for the conversion of HMF into FDCA, a promising substitute for the petroleum derivative terephthalic acid.