Dual‐Site Cascade Mechanism Over Vacancy‐Rich CoO/High‐Spin CoOOH Heterointerfaces Enables Highly Efficient and Ultrastable 5‐hydroxymethylfurfural Electrooxidation

ABSTRACT Electrocatalytic oxidation of 5‐hydroxymethylfurfural (HMF) to 2,5‐furandicarboxylic acid (FDCA) offers a sustainable route for biomass valorization into renewable polyester monomers. However, under alkaline conditions (pH 11.0), non‐precious metal catalysts struggle to achieve low overpotential, high FDCA selectivity, and ultralong stability simultaneously. Herein, density functional theory (DFT) calculations reveal that oxygen vacancy‐rich CoO substantially lowers the energy barrier for HMF to 5‐Hydroxymethyl‐2‐furancarboxylic acid (HMFCA) conversion, while low‐coordination high‐spin CoOOH effectively stabilizes the * OH intermediate to promote deep oxidation. Guided by these insights, we develop ultraviolet laser ablation combined with an electro‐oxidation activation strategy to construct an oxygen vacancy‐rich CoO/low‐coordination high‐spin CoOOH heterostructure catalyst. The catalyst delivers 10 mA cm −2 at merely 1.19 V (vs. RHE), with >98% HMF conversion, near‐100% FDCA selectivity, and stability exceeding 1000 h, setting a new benchmark for non‐precious metal catalysts under comparable conditions. Experiments and various in situ characterizations confirm that the synergistic optimization of the reaction pathway aligns closely with theoretical predictions. This oxygen vacancy‐induced low‐coordination high‐spin state regulation strategy exhibits excellent generality, successfully extended to Ni‐based systems, and demonstrates markedly enhanced performance across various biomass platform molecule electrooxidations. This work provides a new paradigm for designing efficient, stable, and cost‐effective non‐precious metal catalysts for biomass electro‐valorization.