Hydrogen‐Bond‐Assisted Electrocatalytic Semi‐Oxidation of 5‐Hydroxymethylfurfural into 2,5‐Diformylfuran by Operando Dissociated N‐Oxyl Mediator

Abstract The conversion of 5‐hydroxymethylfurfural (HMF) to 2,5‐diformylfuran (DFF) is a promising approach for enhancing biomass utilization. Nevertheless, traditional methods using noble metal catalysts face challenges due to high costs and poor selectivity towards DFF. Herein, we developed a novel catalytic electrode integrating N ‐hydroxyphthalimide (NHPI) into a metal‐organic framework on a hydrophilic carbon cloth. This design significantly enhances the selective adsorption of HMF due to stronger hydrogen‐bond interaction between the electrode's hydrophilic surface and the C(sp 3 )−OH group in HMF compared to the C(sp 2 )=O in DFF. Additionally, the electro‐driven dissociation of the NHPI‐linker generates stabilized N ‐Oxyl radicals that promote selective semi‐oxidation of HMF under neutral conditions. As a result, this approach achieves a high yield rate of 138.2 mol mol cat −1 h −1 with a selectivity of 96.7 % for the HMF‐to‐DFF conversion. This work introduces a novel strategy for designing catalytic electrodes with stabilized N ‐Oxyl radicals, and offers a promising method for electrocatalytic DFF synthesis, leveraging hydrogen‐bond interaction between electrode surface and HMF.