Research in disproportionation reaction mechanism of methyltrichlorosilane and trimethylchlorosilane catalyzed by modified catalyst AlCl_3/ZnCl_2-ZSM-5

摘要

Disproportionation reaction mechanism of methyltrichlorosilane and trimethylchlorosilane catalyzed by modified catalyst AlCl_3/ZnCl_2-ZSM-5 was calculated by DFT(B3LYP/LANL2DZ) method. The conclusions are following: the reaction process which modified catalyst AlCl_3/ZnCl_2-ZSM-5 participated in mainly was divided into main and side reactions. The rate-determining steps of main reaction and side reaction were respectively the first and the third reactions. The active energies of each step were Ea_1=272.3956kJ/mol, Ea_2=207.7569kJ/mol, Ea_3=330.1417kJ/mol, Ea_4=184.0111kJ/mol respectively. The reaction energy barrier of the first step reaction was high, and main reaction occurred difficultly in the catalytic effect of modified catalyst. The reason is that the Lewis acid of the Al position on catalyst decreased, resulting in the catalytic activity becoming small, which is the disadvantage of the disproportionation reaction.