In-situ construction and repair of high catalytic activity interface on corrosion-resistant high-entropy amorphous alloy electrode for hydrogen production in high-temperature dilute sulfuric acid electrolysis

Producing high-purity hydrogen from water electrolysis using intermittent renewable electricity is fascinating and challenging. Noble metal-based high-entropy alloy with near-equimolar mixed elements have unique properties including cocktail effect, high entropy effect and lattice distortion effect, which are beneficial to improve catalytic performance and reduce the amount of noble metal. Taking advantages of excellent mechanical properties, high thermal stability and corrosion resistance, as well as chemical uniformity and tunability, equiatomic high-entropy metallic glass PdPtCuNiP was employed to construct nanosponge-like architecture with uniform nanopores via a precise strategy of potentiostatic electrochemical dealloying, which presented superior hydrogen evolution reaction (HER) electrocatalytic performance in hot dilute H₂SO₄. The Tafel slope is 34.2 mV dec⁻¹ and the overpotential corresponding to 10 mA cm⁻² is 35.4 mV, outperforming commercial Pt/C catalyst and most currently available electrocatalysts. Furthermore, even electrocatalytic performance of nanoporous PdPtCuNiP is degraded tinily by hot dilute H₂SO₄ accordng to power-off or low-voltage operation of water-electrolysis system, it can be directly refreshed by in-situ potentiostatic polarization in the electrolyzer. We believe the strategy of in-situ construction and repair of nanostructured electrocatalytic surface on high-entropy alloy in this study will call for more endeavors to realize the practicality of hydrogen production in harsh acidic electrolyte.