Interfacial assembled CoP and CeO2 heterostructure nanosheets array for efficient 5-hydroxymethylfurfural electrooxidation coupled with hydrogen evolution

Integrating biomass upgrading via electrocatalytic 5-hydroxymethylfurfural oxidation (HMFOR) with the hydrogen evolution reaction (HER) presents a promising strategy to reduce the energy consumption of green hydrogen production while simultaneously generating high-value chemicals. However, the performance and selectivity of electrocatalysts for these reactions still require further improvement. In this work, a CoP-CeO2 heterostructure nanosheet array supported on nickel foam (CoP-CeO2/NF) was developed as an efficient bifunctional electrocatalyst for both HMFOR and HER. The successful construction of the heterointerface was verified through TEM observations, while XPS analysis confirmed interfacial electron transfer from CoP to CeO2. This electronic interaction optimizes the adsorption properties of CoP toward key reaction intermediates, and the abundant oxygen vacancies in CeO2 enhance adsorptive selectivity toward oxygen-containing groups in HMF. As a result, the optimized CoP-CeO2/NF drives HMFOR at a low potential of 1.37 V to achieve 200 mA cm−2 in 1.0 M KOH with 100 mM HMF, and further requires only 1.2 V to reach 10 mA cm−2 in a two-electrode system coupled with HER, which is significantly lower than the voltage required for conventional water electrolysis (1.4–1.6 V). Furthermore, by enhancing the adsorption capability for HMF and reaction intermediates, our electrocatalysts effectively mitigate competition from the oxygen evolution reaction (OER) over a broad potential range, particularly at higher voltages, and maintains a Faraday efficiency above 85 % within 1.3–1.6 V. This work provides a compelling approach to designing bifunctional electrocatalysts for energy-saving green hydrogen production integrated with biomass upgrading.