Bimetallic Fe(OH)_x@Co_0.8Fe_0.2-MOF/NF composites as effective electrocatalysts for the production of 2,5-furandicarboxylic acid from 5-hydroxymethylfurfural

A wide range of catalytic techniques have been explored for the use of biomass components. For example, the electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-furandicarboxylic acid (FDCA) can be performed with excellent energy efficiency under safe operating conditions and with fine control of the production parameters. Metal-organic framework (MOF) catalysts with active metal centres have been prepared as electrocatalysts for the oxidation of HMF to FDCA. A Fe(OH)_x@Co_0.8Fe_0.2-MOF/nickel foam (NF) was made via two steps: Co_0.8Fe_0.2-MOF/NF was synthesized by in situ solvothermal methods followed by the electrodeposition of Fe(OH)_x. X-ray photoelectron spectroscopy (XPS) analysis confirmed the successful electrodeposition of Fe(OH)_x on Co_0.8Fe_0.2-MOF/Ni. Fe(OH)_x@Co_0.8Fe_0.2-MOF/NF demonstrated enhanced electrocatalytic activity for the oxidation of HMF in 1M KOH, requiring an overpotential of 236 mV and 263 mV versus RHE to achieve current densities of 50 and 100 mA cm⁻², respectively, with an apparent Tafel slope of 92 mV. The electrochemically active surface area of the catalysts showed that Fe(OH)_x incorporated samples possessed a higher number of active sites compared to Co_0.8Fe_0.2-MOF/Ni, enhancing efficiency and improving the yield of 5−Hydroxymethylfurfural oxidation reaction (HMFOR).