Sub‑2 nm\nTernary Metallic Alloy Encapsulated\nwithin Montmorillonite Interlayers for Efficient Hydrogen Generation\nfrom Ammonia Borane Hydrolysis

Ultrafine\nmetal alloy nanoparticles are emerging as highly\neffective\ncatalysts for the generation of hydrogen from ammonia borane (AB)\nhydrolysis. The fabrication of multimetallic alloys with high activity,\nstability, and metal utilization remains the biggest challenge. Herein,\nsub-2 nm ternary Rh–Ru–Ni alloys were encapsulated within\nthe interlayers of layer-stripped montmorillonite (MMT) via a simple\nimpregnation method. Experiment and theory results revealed that the\nsynergistic effect of the trimetallic alloy significantly lowers the\nenergy barrier for the AB hydrolysis reaction, by boosting the adsorption\nand O–H dissociation of H<sub>2</sub>O molecules. The optimized\nRh<sub>0.8</sub>Ru<sub>0.2</sub>Ni<sub>0.25</sub>@MMT-S catalyst achieves\nhigh turnover frequency values of 2961 and 784 min<sup>–1</sup> at 298 and 273 K, respectively, as well as high recycling stability\nand thermal resistance. Moreover, the encapsulation method has versatility\nand can be also applied to synthesize ultrafine Pt- and Ir-based nanoparticles.\nThis study not only highlights the role of the synergistic effect\nin trimetallic alloys for improving hydrogen evolution but also offers\na route to design highly efficient and stable metal nanocatalysts\nfor other applications.