Interface engineering of the NiO/CeO₂@NF heterostructure to boost the electro-oxidation of 5-hydroxymethylfurfural

The synthesis of furan-based platform chemicals from abundant and renewable biomass-based hexoses plays an important role in the development and utilization of biomass energy. The electrochemical 5-hydroxymethylfurfural oxidation reaction (HMFOR) represents a promising route for synthesizing the 2,5-furandicarboxylic acid (FDCA) product which is a high value-added biomass-based monomer. Interface engineering is an effective strategy to adjust the electronic structure, optimize the adsorption of intermediates, and expose more active sites, thus attracting extensive attention for designing efficient HMFOR electrocatalysts. Herein, a NiO/CeO₂@NF heterostructure with an abundant interface is designed for boosting the HMFOR performance under alkaline conditions. At 1.475 V vs. RHE, the conversion of HMF is nearly 100%, the selectivity of FDCA is 99.0%, and the faradaic efficiency is as high as 98.96%. The NiO/CeO₂@NF electrocatalyst also exhibits robust stability for HMFOR for 10 cycles. When coupled with the cathode hydrogen evolution reaction (HER) in alkaline medium, the yields of FDCA and hydrogen production are 197.92 and 600 μmol cm^-2 h^-1, respectively. The NiO/CeO₂@NF catalyst is also suitable for the electrocatalytic oxidation of other biomass-derived platform compounds. The abundant interface between NiO and CeO₂, which can regulate the electronic properties of Ce and Ni atoms, improve the oxidation state of Ni species, regulate intermediate adsorption, and promote electron/charge transfer, makes the most contribution to high HMFOR performance. This work will provide a simple route for the design of heterostructured materials and reveal the application prospect of interface engineering for promoting the upgrading of biomass derivatives.