CoP-CoOOH heterojunction with modulating interfacial electronic structure: A robust biomass-upgrading electrocatalyst

The interfacial electron modulation of electrocatalyst is an effective strategy to realize the oxidation of organic chemicals. Here, a heterojunction (CoP-CoOOH) is prepared via a modulating electron density between interfaces for 5-hydroxymethylfurfural (HMF) oxidation to 2,5-furanedioic acid (FDCA) in high concentration. Density Functional Theory (DFT) shows that heterojunction increased efficient charged active centers, enhanced the adsorption of the reactant on the surface of electrocatalyst, and improved the HMF oxidation reaction (HMFOR) activity. The electrolyzer using CoP-CoOOH as cathodic evolution H 2 and anodic HMFOR requires only voltage of 1.42 V. Additionally, the diffusion limitation of the reaction is overcome via coupling with the flow reactor, which further improved the HMFOR efficiency. Although the HMF concentration is 150 mM, the Faraday efficiency of HMF and the selectivity of FDCA in the flow reactor are 98.2 % and 99.4 %, respectively. A simple electrodeposition strategy is employed to construct the CoP-CoOOH heterojunction to enable the HMF high-efficiency electrooxidation. • Coupling the biomass-upgrading with hydrogen evolution is an effective method for improving the utilization of energy. • Heterojunction can modulate the space charge region and improve the adsorption energy of HMF. • In situ Raman confirmed the electrochemical stability of the heterojunction. • Reasonable mechanism for the robust biomass-upgrading activity was well explained.