High-Conductivity Lignin-Derived Carbon Fiber-Embedded CuFe2O4 Catalysts for Electrooxidation of HMF into FDCA

The electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) provides a viable pathway for the efficient utilization of biomass resources. However, designing and regulating the activity and selectivity of the corresponding electrocatalysts remain significant challenge. Spinel compounds show great potential as catalysts due to their adjustable electronic structures and notable catalytic properties, but their intrinsic low conductivity has limited their further application. Herein, a lignin-based carbon fiber (LCF) embedded CuFe₂O₄ catalyst (CuFe₂O₄/LCF) is successfully constructed using an electrospinning technique. The catalyst can efficiently and selectively synthesize 2,5-furandicarboxylic acid (FDCA) at a relatively low potential. The experimental results and theoretical simulations demonstrate that the introduction of lignin can significantly optimize the pregraphitic turbine carbon microstructure of the carbon fibers and facilitate rapid electron transfer between CuFe₂O₄ and the carbon layer. Furthermore, the A_Td–O–B_Oh interactions on the surface of the CuFe₂O₄ spinel structure significantly enhance the adsorption capacity for the substrates and OH^– species, effectively promoting the catalytic reaction. The findings hope to provide a unique perspective to improve the catalytic activity of lignin carbon fiber spinel catalysts and the stability of biomass value-added mechanism.