Pseudo-Ir Os<sub><i>x</i></sub>Pt<sub>1-<i>x</i></sub> Solid Solutions for Ir-Free H<sub>2</sub> Generation from N<sub>2</sub>H<sub>4</sub> Decomposition.

Gao, Junyun; Zheng, Jie; Deng, Hanwen; Tan, Zhe; Zhao, Jiang; Huang, Bo · ACS Nano · 2026

basic_science · Level V

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Abstract

Metallic Ir is known as the most active catalyst for room-temperature H<sub>2</sub> generation from N<sub>2</sub>H<sub>4</sub> decomposition. To improve N<sub>2</sub>H<sub>4</sub>-based H<sub>2</sub> storage technologies, the replacement of the extremely rare and high-cost Ir element is imminent but challenging because of its unique electronic structure. As one of the rational approaches for Ir replacements, immiscible Os<sub><i>x</i></sub>Pt<sub>1-<i>x</i></sub> solid solutions were synthesized. Even with low-activity elements (Os and Pt), Os<sub>0.5</sub>Pt<sub>0.5</sub> showed much higher N<sub>2</sub>H<sub>4</sub> decomposition activity than that of the pure Ir catalyst. According to the <i>in situ</i> Fourier transform infrared measurements and density-functional-theory calculations, the rapid N-N and N-H dissociations and H<sub>2</sub> formations on Os-Os, Os-Pt, and Pt-Pt sites might contribute to ultrafast H<sub>2</sub> generation and N<sub>2</sub>H<sub>4</sub> decomposition of Os<sub>0.5</sub>Pt<sub>0.5</sub> as pseudo-Ir.