CoP nanorods anchored on Ni2P-NiCoP nanosheets with abundant heterogeneous interfaces boosting the electrocatalytic oxidation of 5-hydroxymethyl-furfural

Abstract

The transformation of biomass-derived platform molecules (such as 5-hydroxymethyl-furfural (HMF)) represents a renewable route to produce value-added chemicals and fuels. Herein, we report the design and fabrication of coralline-like CoP/Ni₂P-NiCoP@NC materials composed of multiple metal phosphides embedded in N-doped carbon for efficient electrocatalytic oxidation of HMF to 2,5-furandicarboxylic acid (FDCA). Systematic characterization indicates that the materials possess strong electronic coupling between the abundant heterogeneous interfaces (i.e., CoP, Ni₂P and NiCoP). Density functional theory (DFT) calculation results further suggest that the heterogeneous interfaces in CoP/Ni₂P-NiCoP@NC can regulate the d-band centers of Co and Ni to approach the Fermi level, thus strengthening the electronic interaction at the reaction interfaces and minimizing the energy barrier of the rate-determining step for HMF electro-oxidation. Consequently, the optimal CoP/Ni₂P-NiCoP@NC-600 exhibits excellent HMF oxidation activity with an ultralow potential of 1.32 V vs. RHE at 10 mA cm⁻² in 0.1 M KOH, affording 98.1% FDCA yield and 97.6% Faradaic efficiency (FE) as well as robust cycling durability.