Interfacial electronic modulation in electrochemical reconstructed CoOOHCuO@CeO2 for efficient electrooxidation of 5-hydroxymethylfurfural

Abstract

Addressing the critical need for efficient electrocatalysts in biomass refining and clean energy conversion, this study introduces a novel strategy for constructing efficient and stable electrocatalysts. A CoCu0.5-MOF@CeO2 precursor was successfully fabricated on carbon cloth (CC) via a synergistic hydrothermal-electrodeposition approach, which undergoes in-situ reconstruction during electrochemical activation to form the active CC@CoOOHCuO@CeO2 electrocatalyst with a defined heterointerface. Comprehensive characterization and electrochemical evaluation reveal that modified CeO2 acts as a key electronic modulator. Leveraging its abundant oxygen vacancies and reversible Ce3+/Ce4+ couple, CeO2 directs electron transfer from Cu to Co via interfacial chemical bonds, significantly enriching the electron density of the Co active centers. This effect enhances the material's conductivity, active sites and intrinsic activity. When employed for 5-hydroxymethylfurfural oxidation reaction in 1.0 M KOH, the optimal electrocatalyst achieves near-complete conversion efficiency, with 5-hydroxymethylfurfural conversion, 2,5-furandicarboxylic acid selectivity, and Faradaic efficiency reaching 97.4%, 98.3%, and 96.3%, respectively, and retains this performance over five consecutive cycles. This work not only validates the effectiveness of interfacial electronic modulation but also provides a practical blueprint for designing electrocatalysts for future renewable energy devices.