Oxygenate-induced structural evolution of high-entropy electrocatalysts for multifunctional alcohol electrooxidation integrated with hydrogen production

Abstract

High-entropy compounds have been emerging as promising candidates for electrolysis, yet their controllable electrosynthesis strategy remains a formidable challenge because of the ambiguous ionic interaction and codeposition mechanism. Herein, we report a oxygenates directionally induced electrodeposition strategy to construct high-entropy materials with amorphous features, on which the structural evolution from high-entropy phosphide to oxide is confirmed by introducing vanadate, thus realizing the simultaneous optimization of composition and structure. The representative P-CoNiMnWVO_x shows excellent bifunctional catalytic performance toward alkaline hydrogen evolution reaction and ethanol oxidation reaction (EOR), with small potentials of -168 mV and 1.38 V at 100 mA cm^-2, respectively. In situ spectroscopy illustrates that the electrochemical reconstruction of P-CoNiMnWVO_x induces abundant Co-O species as the main catalytic active species for EOR and follows the conversion pathway of the C₂ product. Theoretical calculations reveal the optimized electronic structure and adsorption free energy of reaction intermediates on P-CoNiMnWVO_x, thereby resulting in a facilitated kinetic process. A membrane-free electrolyzer delivers both high Faradaic efficiencies of acetate and H₂ over 95% and superior stability at100 mA cm^-2 during 120 h electrolysis. In addition, the unique composition and structural advantages endow P-CoNiMnWVO_x with multifunctional catalytic activity and realize multipathway electrosynthesis of formate-coupled hydrogen production.