Self-supported FeCoNiCuP high-entropy alloy nanosheet arrays for efficient glycerol oxidation and hydrogen evolution in seawater electrolytes

Abstract

The development of highly efficient and bifunctional electrocatalysts for hydrogen evolution and glycerol oxidation in seawater electrolytes is of great significance for the production of high value-added chemicals. Herein, self-supported FeCoNiCuP high entropy alloy nanosheet arrays (HEANAs) were successfully synthesized on a carbon cloth substrate through a straightforward electrodeposition method. The resulting catalyst demonstrates remarkable performance towards glycerol oxidation reaction (GOR) with a low potential of 1.28 V at 10 mA cm⁻² and an impressive formate Faradaic efficiency (FE) of 87.9%. Additionally, this catalyst exhibits excellent hydrogen evolution reaction (HER) performance. Theoretical calculations identify Fe and CuNiFe bridge sites of FeCoNiCuP as active centers for GOR and HER, respectively. Utilizing FeCoNiCuP HEANAs in the GOR-assisted electrolyzer achieves a substantially reduced potential of 1.40 V at 10 mA cm⁻², producing formate at the anode and hydrogen at the cathode with high FE and outstanding stability. Furthermore, the catalyst maintains consistent performances in seawater electrolyte without interfering with chlorine evolution, offering a promising avenue for sustainable and environmentally friendly high-value chemical production.