Liquid Gallium–Zeolite Nanocomposite Catalysts for Propane Dehydrogenation

Liquid metal (LM) with outstanding fluidity, excellent electrical and thermal conductivity is emerging in heterogeneous catalysis, such as Ga-based supported catalytically active liquid-metal solutions. However, liquid gallium droplets are prone to migration and aggregation, especially under high-temperature reaction conditions. Herein, we designed a liquid gallium-zeolite nanocomposite catalyst (L-Ga/S-1) by a simple and low-cost physical mixing method. In propane dehydrogenation, the optimized L-1.5-Ga/S-1 exhibited a high formation rate of 1.17 mol C3H6gGa–1 h–1, 13 times higher than that of 1.5-Ga-MFI, with a propylene selectivity of up to 95% at 550 °C. It could be ascribed to abundant interface GaOx structure between Ga droplet and nanosized Silicalite-1 zeolite, which provided strong Lewis acidic sites to promote the selective scission of C–H bonds. Liquid metal–metal oxide nanocomposites offer an important way for controlling interface precisely in the sphere of heterogeneous catalysis.