In Situ Engineering Multifunctional Active Sites of Ruthenium–Nickel Alloys for pH‐Universal Ampere‐Level Current‐Density Hydrogen Evolution

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2024-08, Vol.20 (34), p.e2311509-n/a
• Main Authors: Liu, Yang, Shi, Hang, Dai, Tian‐Yi, Zeng, Shu‐Pei, Han, Gao‐Feng, Wang, Tong‐Hui, Wen, Zi, Lang, Xing‐You, Jiang, Qing
• Format: Article
• Language: English
• Subjects: Acidic oxides; alloy; Alloys; Catalysts; Electrocatalysts; Electrodes; Graphene; Hydrogen; Hydrogen evolution reactions; Hydrogen production; hydrogen revolution reaction; Nanoalloys; Nanoparticles; Nickel base alloys; Nickel compounds; Platinum; Ruthenium; Sulfuric acid; Water splitting
• ISSN: 1613-6810; 1613-6829; 1613-6829
• DOI: 10.1002/smll.202311509

Developing robust non‐platinum electrocatalysts with multifunctional active sites for pH‐universal hydrogen evolution reaction (HER) is crucial for scalable hydrogen production through electrochemical water splitting. Here ultra‐small ruthenium‐nickel alloy nanoparticles steadily anchored on reduced graphene oxide papers (Ru‐Ni/rGOPs) as versatile electrocatalytic materials for acidic and alkaline HER are reported. These Ru–Ni alloy nanoparticles serve as pH self‐adaptive electroactive species by making use of in situ surface reconstruction, where surface Ni atoms are hydroxylated to produce bifunctional active sites of Ru‐Ni(OH)2 for alkaline HER, and selectively etched to form monometallic Ru active sites for acidic HER, respectively. Owing to the presence of Ru‐Ni(OH)2 multi‐site surface, which not only accelerates water dissociation to generate reactive hydrogen intermediates but also facilitates their recombination into hydrogen molecules, the self‐supported Ru90Ni10/rGOP hybrid electrode only takes overpotential of as low as ≈106 mV to deliver current density of 1000 mA cm−2, and maintains exceptional stability for over 1000 h in 1 m KOH. While in 0.5 m H2SO4, the Ru90Ni10/rGOP hybrid electrode exhibits acidic HER catalytic behavior comparable to commercially available Pt/C catalyst due to the formation of monometallic Ru shell. These electrochemical behaviors outperform some of the best Ru‐based catalysts and make it attractive alternative to Pt‐based catalysts toward highly efficient HER. Ru–Ni alloy nanoparticles anchored on reduced graphene oxide papers are developed as robust and pH‐universal electrocatalysts for hydrogen evolution reaction by making use of surface reconstructions to form multisite surface of Ru‐Ni(OH)2 or monometallic Ru in nonacidic or acidic environment. The pH self‐adaptivity enlists Ru–Ni alloy to exhibit outstanding electrocatalysis towards alkaline and acidic hydrogen evolution reactions.