Electrochemical valorization of HMF using Ni/Graphite electrodes

• Published in: Materials chemistry and physics 2024-01, Vol.311, p.128510, Article 128510
• Main Authors: Carvajal, David, Arcas, Ramón, Gouda, Laxman, Fabregat-Santiago, Francisco, Mas-Marzá, Elena
• Format: Article
• Language: English
• Subjects: Biomass; Electrochemistry; FDCA; HMF; Impedance spectroscopy; Ni-based electrodes
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2023.128510

The electrooxidation of 5-hydroxymethylfurfural (HMF) into 2,5- furandicarboxilic acid (FDCA) has been successfully accomplished using cost-effective NiO–OH electrodes, prepared through Ni electrodeposition on pencil graphite rods (Ni/PGR). Through meticulous optimization of the reaction conditions to prevent HMF degradation, we achieved almost complete conversion of HMF into FDC, in less than 2 h, with a remarkable 88 % Faraday efficiency. Electrochemical analyses have confirmed that our Ni(OH)2/NiOOH• catalyst requires a 0.16 V lower overpotential for HMF oxidation compared to water oxidation. Fitting the Impedance Spectroscopy (IS) spectra of the system have allowed us to elucidate, the details of the electrical response associated to HMF oxidation. These studies have revealed that following HMF activation, the surface of the Ni/PGR electrode remains coated with the reaction intermediates, thus triggering the complete oxidation to FDCA. [Display omitted] •Biomass valorization accomplished using cost-effective NiO–OH electrodes.•Meticulous optimization of the reaction conditions to prevent biomass degradation.•Impedance analysis allow to detect adsorption of intermediate on the electrode.