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 H₂ generation from N₂H₄ decomposition. To improve N₂H₄-based H₂ 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_<i>x</i>Pt_1-<i>x</i> solid solutions were synthesized. Even with low-activity elements (Os and Pt), Os_0.5Pt_0.5 showed much higher N₂H₄ 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 H₂ formations on Os-Os, Os-Pt, and Pt-Pt sites might contribute to ultrafast H₂ generation and N₂H₄ decomposition of Os_0.5Pt_0.5 as pseudo-Ir.