Study on the mechanism of catalytic synthesis of dimethyldichlorosilane by AlCl₃/MIL‐53(Al)@γ‐Al₂O₃

Abstract

Dimethyldichlorosilane, one of the most consumed organosilicon monomers in the industry, can be prepared in a highly efficient and environmentally friendly synthesis method of disproportionating methylchlorosilanes. However, the internal mechanism of the reaction remains unclear. In this paper, the mechanism catalyzed by AlCl 3 /MIL-53(Al) and AlCl 3 /MIL-53(Al) @γ-Al 2 O 3 catalysts was calculated at B3LYP/6-311++G(3df, 2pd) level by using the density functional theory (DFT). The results showed that although the two catalysts had similar active structures, the catalytic effects were significantly different. The Lewis acid center on the surface of γ-Al 2 O 3 in the core-shell catalyst is complementary to the classic Lewis acid AlCl 3 through the spatial superposition effect, which greatly improves the Lewis acid catalytic activity of AlCl 3 /MIL-53(Al)@γ-Al 2 O 3 .