Facile and Environmentally Friendly Synthesis of Ga₂O₃/MFI Catalysts for Propane Dehydrogenation

A GaO-based catalyst is recognized as a promising catalyst for dehydrogenation of light alkanes. Conventionally, impregnation and calcination are necessary processes for the loading of GaO. However, the incomplete impregnation of gallium salt solution would generate wastewater, and the calcination for the dissociation of gallium salt would release harmful gases, such as SO, NO, and HCl. Meanwhile, the high temperature results in an excessive energy cost and undesired GaO particle aggregation. Here, we report a facile and environmentally friendly method for the synthesis of GaO-based catalysts. The gallium salt solution was replaced directly with liquid gallium (LG). Through a simple physical mixing method at room temperature, uniform GaO nanoparticles with diameters of around 3.5 nm were loaded onto the surface of silicalite-1 (S-1). With the optimal GaO/MFI catalyst, the propane conversion and propylene selectivity reached 22.9 and 90.1%, respectively, in the propane dehydrogenation reaction. The work offers a clean and economical strategy utilizing liquid metal (LM) as an impregnation solution for the preparation of GaO-based catalysts.