Heterogeneous interface induced Co3O4-NiO catalyst for efficient electrocatalytic 5-Hydroxymethylfurfural oxidation

The electrooxidation of 5-hydroxymethylfurfural (HMF) provides an efficient and environmentally friendly approach to obtain high-value chemicals from biomass. In this study, porous nanocube framed Co3O4-NiO electrocatalysts with heterogeneous interface are constructed for efficient HMF oxidation reaction (HMFOR). The heterogeneous interface modulates the electronic properties of Co and Ni atoms, enhances the oxidation state of Ni species, which is favorable for the oxidation of HMF. Compared to pure Co3O4 and NiO, Co3O4-NiO exhibits a lower onset potential (1.22 V vs. RHE), higher FDCA yield (83.33 %) and Faraday efficiency (89.47 %). Furthermore, the results of open circuit potential (OCP), high-performance liquid chromatography (HPLC) product analysis and in-situ electrochemical impedance spectroscopy (EIS) demonstrate that the Co3O4-NiO heterogeneous interface effectively enhances the adsorption and transformation of organic molecules and OH– species, and facilitates the further oxidation of 5-formyl-2-furancarboxylic acid (FFCA) to 2,5-furandicarboxylic acid (FDCA), thus improving the performance of HMFOR. This work illustrates the effect of heterogeneous interface on Co3O4-NiO catalyst for HMFOR and provides a direction for the development of high-performance electrocatalysts for HMFOR.