Preparation and redistribution mechanism of dimethyldichlorosilane catalyzed by the AlCl3/ZSM-5(5T)@MIL-53(Al) core–shell catalyst

Abstract

Dimethyldichlorosilane, which is the most important organic silicon monomer, can be prepared using a novel core–shell catalyst. However, the debate continues regarding its redistribution mechanism. In the current study, the redistribution mechanism catalyzed by the ZSM-5(5T)@MIL-53(Al) catalyst was theoretically studied via density functional theory on the level of M06-2X/def2-TZVP. Then, the catalytic performances of different active centers modified with AlCl₃ were evaluated. The results showed that the active center of the former was Brønsted acid, while that of the latter modified by AlCl₃ was Lewis acid. In addition, Lewis acid increased the catalytic activity in comparison with Brønsted acid. The calculations of activation energy, frequency vibrational analysis, bond order analysis, frontier molecular orbital theory, electronic localization function, and localized orbital locator analyses were in agreement with the said mechanism and results.