CeO ₂ ‐Modified Ni ₃ N as Highly Efficient Bifunctional Electrocatalysts for 5‐Hydroxymethylfurfural Oxidation Coupled With Hydrogen Evolution

ABSTRACT The development of electrocatalysts with excellent water splitting and 5‐hydroxymethylfural oxidation reaction (HMFOR) performance can relieve energy challenges and environmental issues. This study constructs a self‐supported CeO 2 ‐Ni 3 N/NF composite on nickel foam (NF) through an elemental modification strategy, developing an electrocatalyst with outstanding electrochemical water splitting and HMFOR performance. The modified CeO 2 introduces oxygen vacancy defects in Ni 3 N and optimizes its electronic structure. The reaction mechanism of HMFOR was explored using in situ characterizations, revealing that CeO 2 not only promotes the complete reconstruction of Ni 3 N into active NiOOH species but also enhances charge transfer of the HMFOR process. CeO 2 modulates the adsorption of reactant on the Ni active sites, thereby mitigating the reduction in reaction activity caused by competitive adsorption. Additionally, CeO 2 reduces the activation energy needed for the intermediate step from *FFCA to *FDCA. By substituting the anodic reaction with HMFOR, the voltage for water splitting can be reduced, while simultaneously generating valuable organic compounds during hydrogen evolution. Specifically, utilizing HMFOR to replace the traditional anodic reaction in water electrolysis only needs 1.43 V to realize 50 mA cm −2 , with a Faradaic efficiency (FE) for cathodic hydrogen evolution approaching 100%, a superior HMF conversion rate (93.6%), and FDCA yield (93.4%). This research provides significant insights for designing transition metal‐based catalysts with excellent electrolytic water and HMFOR performance.