Pseudo-Ir Os _<i>x</i> Pt _{1– <i>x</i>} Solid Solutions for Ir-Free H ₂ Generation from N ₂ H ₄ Decomposition

Metallic Ir is known as the most active catalyst for room-temperature H 2 generation from N 2 H 4 decomposition. To improve N 2 H 4 -based H 2 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 x Pt 1– x solid solutions were synthesized. Even with low-activity elements (Os and Pt), Os 0.5 Pt 0.5 showed much higher N 2 H 4 decomposition activity than that of the pure Ir catalyst. According to the in situ Fourier transform infrared measurements and density-functional-theory calculations, the rapid N–N and N–H dissociations and H 2 formations on Os–Os, Os–Pt, and Pt–Pt sites might contribute to ultrafast H 2 generation and N 2 H 4 decomposition of Os 0.5 Pt 0.5 as pseudo-Ir.