ACS Nano - Highly Distorted High-Entropy Alloy Aerogels for High-Efficiency Hydrogen Oxidation Reaction

Hanjun Li, Fulin Yang*, Guanghua Wang*, Liheng Guan, Feili Lai, Nan Zhang*, Tianxi Liu*

ACS Nano 2025, DOI: 10.1021/acsnano.5c02198

The development of efficient electrocatalysts for alkaline hydrogen oxidation reaction (HOR) is essential for anion exchange membrane fuel cells and advancing the hydrogen economy. Herein, we demonstrated PtRuRhPdIr high-entropy alloy aerogels (HEAAs) with highly distorted structure as efficient HOR electrocatalysts and realized effective control of PtRu-based metallic aerogels (MAs) with elemental components ranging from two to seven. Specially, PtRuRhPdIr HEAAs on carbon (PtRuRhPdIr HEAAs/C) exhibit excellent HOR activity, with Pt group metal (PGM)-normalized mass activity (5.75 A mgPGM–1) at 50 mV and exchange current density normalized by electrochemical surface area (0.69 mA cm–2), approximately 16.9 and 4.1 times that of the commercial Pt/C (0.34 A mgPGM–1, 0.17 mA cm–2), respectively. The mechanism study shows that the highly distorted PtRuRhPdIr HEAAs provide abundant unsaturated sites for HOR, and the synergistic effect of multiple-active sites balances the adsorption of H* and *OH, boosting the HOR performance.

Link: https://doi.org/10.1021/acsnano.5c02198