Multi-scale regulation to NiCo hydroxides by ionic liquid for high-performance electrocatalytic HMF oxidation

The key issue in electricity-drive 5-Hydroxymethylfurfural oxidation reaction (HMFOR) is to accelerate the electrochemical protons deintercalation process of catalyst for reducing the reaction potential and improving the reaction activity. Herein, we developed a novel ionic liquid (IL) modification strategy to construct 1-butyl-3-methylimidazolium trifluoroacetate modified Co 2 Ni( OH ) x ([BMIm][TFA]-Co 2 Ni( OH ) x /NF) catalyst. The introduction of IL provides assistance in the morphological structural and electronic configuration modulation, thereby enhancing mass transfer efficiency and the generation of high-valent active species (TFA-M 2+ -OH ⇌ TFA-M 3+ -O). Benefit from the above favorable regulatory strategies, the resulting [BMIm][TFA]-Co 2 Ni( OH ) x /NF exhibits remarkable low onset potential (1.13 V vs. RHE), high current density (97 mA/cm 2 at 1.40 V vs. RHE), and excellent FDCA yield (98%) with high Faradaic efficiency (98%) across a wide potential range (1.44–1.50 V vs. RHE). In addition, the experimental results reveal that IL modification strategy impedes overcover of *OH and hereby effectively suppressed OER process, thus maintaining excellent HMFOR reactivity over a wide voltage range. This route provides a novel and green ligand modification scheme for enhancing the synergistic effect of Ni/Co sites in CoNi hydroxides and rapidly formation of active species for HMFOR.