Cobalt and nitrogen co-modified graphitic carbon: a bifunctional catalyst for thermocatalytic and electrocatalytic oxidation of HMF to FDCA

Biomass energy has gained significant attention due to its renewability and clean, low-carbon characteristics. We prepared a Co@NC-a catalyst using the complexation-carbonation-acid etching method, which can catalyze both thermochemical and electrochemical HMF selective oxidation reactions. In thermocatalysis, it can achieve 100% HMF conversion and 94.4% FDCA yield at 65 °C and 0.2 MPa O2. In electrocatalysis, 100% HMF conversion and 73% FDCA yield were also realized. Significantly, graphitized carbon contributes to the aerobic oxidation of HMF due to its excellent electrical conductivity, which promotes electron transfer during the reaction. Additionally, a comparative study of the activation energy of this catalytic system in electrocatalysis and thermocatalysis showed that electrocatalysis is kinetically more favorable. The energy efficiency calculation also indicates electrocatalysis is more energy efficient than thermocatalysis.