Synergistically Enhanced Co-Adsorption of HMF and Hydroxyl on Selenium and Oxygen Dual Vacancies in CeO2-CuNiSe2/NF for High-Efficiency HMF Electrooxidation

Abstract

Electrocatalytic conversion of biomass-derived 5-hydroxymethylfurfural (HMF) into 2,5-furandicarboxylic acid (FDCA) represents a sustainable route for value-added chemical production. However, the sluggish reaction kinetics, caused by inadequate adsorption of HMF and OH- on catalyst surfaces, remains a major challenge. Herein, we construct a CeO2-CuNiSe2/NF catalyst with oxygen and selenium vacancies by triggering a charge compensation mechanism via Cu2+ modification of NiSe2 and introducing CeO2. The optimized CeO2–CuNiSe2/NF catalyst delivered an exceptional current density of 1.23 A cm-2 at 1.5 V (vs. RHE), outperforming its unmodified counterparts with approximately 3.15-fold, 2.16-fold, and 1.82-fold enhancements over NiSe2/NF, CuNiSe2/NF, and CeO2–NiSe2/NF, respectively. Notably, the catalyst maintains performance above 95% over 10 consecutive cycles, demonstrating outstanding operational stability. In situ electrochemical impedance spectroscopy (EIS) confirmed that the engineered dual vacancies (Se and O vacancies) effectively reduced the interfacial resistance and significantly enhanced the interfacial reaction kinetics of the catalyst. Theoretical calculations confirm that the Se and O vacancies promote HMF adsorption and OH- capture, collectively reducing the reaction energy barrier of the rate-determining step (FFCA* to FDCA*). This study establishes a novel designing highly efficient HMFOR catalysts strategy that enhance co-adsorption performance through construction of dual vacancies.