Uncovering the electrooxidation behavior of 5-hydroxymethylfurfural on Ni/Co electrodes

Biomass, derived from plant photosynthesis that captures carbon dioxide to form carbohydrates, offers vast renewable reserves. The electrooxidation of biomass, coupled with the hydrogen evolution reaction, enables the simultaneous production of biomass-based plastic monomers and green hydrogen, attracting significant scholarly interest. However, ambiguity remains regarding the adsorption mechanism at the catalyst surface (Langmuir-Hinshelwood or Eley-Rideal) and the adsorbed substrate groups. To address this, we prepared a Ni/Co electrode for the electrooxidation of 5-hydroxymethylfurfural (HMF) into 2,5-furandicarboxylic acid (FDCA) through a corrosion reaction and electro-reduction pathway. HMF conversion reached 100.00%, FDCA yield reached 96.82%, and Faradic efficiency (FE) reached 92.14%. Meaningfully, utilizing in-situ spectroscopy and electrochemical methods, this work provided valuable insights into active sites and catalyst surface adsorption.