Mechanism of dimethyldichlorosilane preparation by NH₂-MIL-53(Al) @-Al₂O₃ core-shell catalyst before and after AlCl₃ modification

The irreplaceable silicone materials among the high-tech industry is dimethyldichlorosilane, a monomer whose by-products generated in the synthesis step can be recycled through disproportionation reactions. In this paper, the catalytic activities of NH2-MIL-53(Al)@gamma-Al2O3 with Bronsted acid active sites and AlCl3/NH2-MIL-53(Al) @gamma-Al(2)O(3 )core-shell catalysts with Lewis acid active sites were investigated and compared for the disproportionation to prepare dimethyldichlorosilane by means of the M06-2X/Def2-TZVP hybrid functional method. The results given for structure, energy, vibrational frequency, IRC values, bond order, ELF and LOL analysis were matched. The results showed that AlCl3/NH2-MIL-53(Al)@gamma-Al2O3 core-shell catalyst with Lewis acid was more active.