Cr-doped NiFe layered double hydroxide nanosheets for electrocatalytic upgrading of biomass-derived 5-hydroxymethylfurfural

The electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) is an effective method to produce high-value-added chemicals with low energy consumption. In this work, we prepared a highly efficient electrocatalyst by incorporating Cr-doped NiFe layered double hydroxide nanosheets supported on nickel foam (NiFeCr-LDH/NF). For the HMF oxidation reaction (HMFOR) in 1   M KOH electrolyte, the NiFeCr-LDH/NF catalyst achieves an exceptional current density of 100   mA   cm -2 at a low potential of 1.47   V vs . reversible hydrogen electrode (RHE). Critically, it exhibits a high 2,5-furandicarboxylic acid (FDCA) yield of 93.8% and a Faradaic efficiency of 91.5%. Furthermore, in situ Fourier transform infrared spectroscopy (FTIR) studies and transient electrochemical measurements were carried out to investigate the mechanism in the HMFOR. Precisely controlled Cr doping can effectively modulate the synergistic adsorption equilibrium between HMF and hydroxyl intermediates, thereby enhancing electrocatalytic reaction efficiency via optimized interfacial charge transfer dynamics. This work illustrates heteroatom engineering as a powerful strategy for designing efficient electrocatalysts, enabling efficient biomass valorization.