Design of Hierarchical CeO ₂ @Co‐Ni ₃ S ₂ Catalyst for Rapid High‐Valent Ni ³⁺ Generation and Optimized Organic Adsorption Toward Enhanced Biomass Conversion

Abstract Nickel‐based sulfides hold great potential for the electrocatalytic oxidation of 5‐hydroxymethylfurfural (HMF) to the high‐value‐added product 2,5‐furandicarboxylic acid (FDCA). However, the rapid construction of high‐valent metal active centers and the enhancement of HMF adsorption capacity on the catalyst surfaces remain critical challenges. In this work, a hierarchical CeO ₂ @Co‐Ni ₃ S ₂ catalyst with abundant electron‐deficient Ni sites is designed for efficient HMF oxidation reaction (HMFOR). Experimental and theoretical analyses demonstrated that the strong electron‐withdrawing capability of CeO ₂ accelerated the formation of high‐valent Ni ³⁺ active centers, while Co doping enhanced the electron transfer capacity of catalyst and optimized HMF adsorption energy, thereby boosting HMFOR kinetics. The synergistic effect of CeO ₂ and Co species enabled the CeO ₂ @Co‐Ni ₃ S ₂ /NF catalyst to achieve a current density of 100 mA cm ⁻² at a low potential of 1.33 V _RHE , which is ≈5.9 times higher than that of Ni ₃ S ₂ /NF. Remarkably, the FDCA yield and Faradaic efficiency reached 99.0% and 99.1%, respectively. This study provides a novel strategy for designing high‐performance transition metal‐based electrocatalysts for biomass conversion.