Self‐Reconstruction of High Entropy Alloys for Efficient Alkaline Hydrogen Evolution

Abstract

Abstract Alkaline water (H 2 O) electrolysis is currently a commercialized green hydrogen (H 2 ) production technology, yet the unsatisfactory hydrogen evolution reaction (HER) performance severely limits its energy conversion efficiency and cost reduction. Herein, PtRu 2.9 Fe 0.15 Co 1.5 Ni 1.3 high entropy alloys (HEAs) is synthesized and subsequently exploited electrochemically induced structural oxidation processes to construct self‐reconfigurable HEAs, as an efficient alkaline HER catalyst. The optimized self‐reconstructed PtRu 2.9 Fe 0.15 Co 1.5 Ni 1.3 HEAs with the HEAs and cobalt rutheniate interface (HEAs‐Co 2 RuO 4 ) exhibits excellent alkaline HER performance, requiring just 11.8 mV to obtain a current density ( j ) of 10 mA cm −2 in 1 m KOH. And the j on HEAs‐Co 2 RuO 4 is 41.8 mA cm −2 at 0.07 V RHE , 2.0 and 6.1 times higher than PtRu 2.9 Fe 0.15 Co 1.5 Ni 1.3 HEAs and 20% Pt/C. Mechanism studies reveal that the improved alkaline HER performance of HEAs‐Co 2 RuO 4 is due to the formation of HEAs‐Co 2 RuO 4 , which significantly shrinks the Helmholtz layer, provides a new fast material transport channel, boosts H 2 O adsorption, and reduces hydrogen adsorption, and thus accelerates the alkaline HER. This research not only throws new light on the self‐reconstruction of catalysts but also provides guidance for the rational design of efficient electrocatalysts.