Preparation of Nb- and Fe-doped CoP-based catalysts for the conversion of high-concentration 5-hydroxymethylfurfural to 2,5-furandicarboxylic acid

Designing low-cost, high-performance electrocatalysts for the electrocatalytic oxidation of 5-hydroxymethylfurfural (HMF) to produce 2,5-furandicarboxylic acid (FDCA) remains a significant challenge. Herein, we report a novel post-pyrolysis phosphidation method for preparing Nb- and Fe-doped CoP-based catalysts. Nb-CoP@NC delivers a current density of 91.79 mA cm⁻² at a potential of only 1.50 V vs. RHE, achieving nearly 100 % HMF conversion, 98.3 % FDCA selectivity, and 95.6 % Faradaic efficiency (FE). Structural and surface analyses via XRD and XPS reveal that Nb doping significantly modulates the electronic structure of CoP, generating Nb 5+δ active species, which show superior catalytic activity for HMFOR compared to Fe 3+δ . This work not only highlights the pivotal role of Nb doping in enhancing catalytic performance but also provides a general and facile strategy for constructing efficient bimetallic CoP-based catalysts for biomass-derived HMF oxidation.