Phosphorus-assisted reconstruction creates NiOOH/CoOOH interfaces for efficient biomass-derived 5-hydroxymethylfurfural electrooxidation

Although cobalt (Co) and phosphorus (P) are widely employed to enhance the electrooxidation performance of Ni-based electrocatalysts, their synergistic roles in regulating metal-site activation and interfacial reconstruction during 5-hydroxymethylfurfural (HMF) oxidation remain unclear. Herein, by comparatively studying the electrochemical behavior and structural evolution of Ni-P/NF and Ni 0.8 Co 0.2 -P/NF during the HMF oxidation reaction (HMFOR), we identify a Co-P synergistic reconstruction mechanism that governs the dynamic formation of active interfaces. Ni 0.8 Co 0.2 -P/NF delivers a low onset potential of 1.33 V (vs. RHE) in 50 mM HMF-containing alkaline electrolyte and achieves a high current density of 900 mA cm −2 at 1.60 V (vs. RHE), with a Faradaic efficiency of 97 % toward FDCA. Mechanistic studies reveal that Co modulates the initial electronic structure of Ni sites, while P stabilizes the evolution of Co species into CoOOH under reaction conditions. The in situ generated CoOOH dynamically couples with neighboring Ni sites, thereby promoting the low-potential reconstruction of Ni 2+ into active NiOOH. In situ Raman spectroscopy further confirms the formation of a stable NiOOH/CoOOH composite active interface during HMFOR, which accounts for the reduced onset potential and accelerated reaction kinetics. This work highlights the importance of coupling static electronic modulation with dynamic electrochemical reconstruction, providing mechanistic insights for the rational design of multicomponent electrocatalysts for biomass-derived 5-hydroxymethylfurfural electrooxidation.