Bidirectional Protonic-Electronic Modulation Based on Self-Adaptive Hydrogen Bond Network for 5-Hydroxymethylfurfural Oxidation

Enhancing interfacial hydrogen bond (HB) network connectivity has been demonstrated as an effective strategy to accelerate 5-hydroxymethylfurfural electrooxidation by facilitating proton transfer. However, conventional HB networks lack structural flexibility, which severely restricts the mass diffusion of HMF and the products, thereby compromising the overall reaction rate. To overcome this limitation, a dynamically responsive HB network is constructed via self-adaptive W doping into nickel–iron hydroxide (W-NiFe), which not only ensures smooth reactant/product transport but also enables bidirectional modulation of external proton and internal electron transfer. On the protonic side, hydroxyl is selectively adsorbed and coordinates with interfacial K+ to directionally recruit free water molecules, thereby reinforcing HB network connectivity. This intelligently engineered network dynamically serves as a rapid proton-relay pathway, promptly dispersing the accumulated protons, mitigating localized acidification, and stabilizing the high-valence Ni sites. Concurrently, on the electronic side, W drives the fast generation of active high-valence Ni species by enabling a directed and swift electron transfer from Ni to W. Benefiting from this synergistic modulation, the optimized W-NiFe requires a low potential of 1.36 V to achieve 10 mA cm–2 and yields 2,5-furandicarboxylic acid with a high Faradaic efficiency of 95.49%. Moreover, thanks to the suppressed acid corrosion, W-NiFe can stably operate for ∼300 h at a high current density of 500 mA cm–2. This work provides fundamental insight into the design of adaptive interfacial structures for advanced electrocatalytic biomass refining.