Embedded Ir─Ru Single-Atom Alloy with Self-Limiting Motifs for Sustainable Proton Exchange Membrane Water Electrolysis.

Li, Shaoxiong; Deng, Liming; Hung, Sung-Fu; Zhao, Sheng; Wang, Luqi; Hao, Yixin; Long, Yongde; Li, Boyuan et al. · Adv Mater · 2026

basic_science · Level V

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Abstract

Designing acid-stable anodic electrocatalysts with low noble-metal loading is essential for the industrial-scale application of proton exchange membrane water electrolysis (PEMWE). However, existing catalyst systems struggle to fully utilize the intrinsic properties of active sites. Here, a precisely engineered nanocatalyst is unveiled through a hierarchical atomic assembly strategy for synthesis, featuring an ultralow-content Ir─Ru single-atom alloy integrated into robust titanium dioxide nanowires (Ir<sub>1</sub>Ru/TiO<sub>2</sub>). This lattice-embedded structure induces the support to reduce the dissolution and excessive oxidation of Ru/Ir sites through strong interfacial coupling, significantly enhancing the corrosion resistance of catalysts. Moreover, atomically dispersed Ir induces the formation of uniquely shortened Ru─O ligand bonds, serving as stable self-limiting motifs, in contrast to the conventional formation of amorphous oxide layers. The Ir<sub>1</sub>Ru/TiO<sub>2</sub> catalyst showcases an initial mass activity of 1971.5 A <math xmlns="http://www.w3.org/1998/Math/MathML"> <semantics><msubsup><mi>g</mi> <mrow><mi>Ir</mi> <mo>+</mo> <mi>Ru</mi></mrow> <mrow><mo>-</mo> <mn>1</mn></mrow> </msubsup> <annotation>${\mathrm{g}}_{{\mathrm{Ir + Ru}}}^{ - {\mathrm{1}}}$</annotation></semantics> </math> , enabling stable operation at 10 mA cm<sup>-2</sup> for over 3200 h and at the rated current density of 2 A cm<sup>-2</sup> for 2000 h in PEMWE.