The redistribution method plays an important role in addressing the issue of organosilicon by-products in the direct synthesis of dichlorodimethylsilane, and the redistribution mechanism is still a topic of debate. The redistribution mechanism by the ZSM–5(3 T)@γ–Al₂O₃ core–shell catalyst and post-modified AlCl₃/ZSM–5(3 T)@γ–Al₂O₃ catalyst was technically performed using the Density functional theory (DFT) at the level of B3LYP/6–311 + + G(3df,2pd). The results show that no. 1 active site of ZSM–5(3 T)@γ–Al₂O₃ core–shell structure has a significant effect on the activity of the catalyst. Indicating that the active center involved in the reaction is H provided by the Al–O–H bond, which is an obvious catalytic active center of Bronsted acid. Furthermore, the post-modified AlCl₃/ZSM–5(3T)@γ–Al₂O₃ catalyst is in more favor of redistribution reaction comparing with the ZSM–5(3 T)@γ–Al₂O₃ core–shell catalyst. It ascribes to the robust Lewis site of aluminum chloride favorable modification.

Graphical abstract

The redistribution synthesis mechanism of dichlorodimethylsilane on the ZSM–5(3 T)@γ–Al₂O₃ core–shell catalyst and post-modified AlCl₃/ZSM–5(3 T)@γ–Al₂O₃ catalyst had been investigated by using the Density functional theory (DFT) method at the level of B3LYP/6–311 + + G(3df,2pd). The former active center was Bronsted acidic center, while the latter one was Lewis acidic center, ascribing to the Lewis site of aluminum chloride favorable modification. The catalytic activity of the post-synthesis AlCl₃/ZSM–5(3 T)@γ–Al₂O₃ catalyst completely was consistent with experimental results.

中文翻译：

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AlCl3/ZSM-5(3T)@γ-Al2O3核壳催化剂再分布合成二氯二甲基硅烷的机理

再分配法在解决二氯二甲基硅烷直接合成中有机硅副产物的问题上发挥了重要作用，而再分配机制仍是一个争论的话题。ZSM–5(3 T)@γ–Al ₂ O ₃核壳催化剂和后修饰的AlCl ₃ /ZSM–5(3 T)@γ–Al ₂ O ₃催化剂的再分配机制在技​​术上使用B3LYP/6–311 + + G(3df,2pd) 水平的密度泛函理论 (DFT)。结果表明没有。1 ZSM–5(3 T)@γ–Al ₂ O _{3 的}活性位点核壳结构对催化剂的活性有显着影响。表明参与反应的活性中心是由Al-O-H键提供的H，是Bronsted酸明显的催化活性中心。此外，与ZSM-5(3 T)@γ-Al ₂ O ₃核-壳相比，后改性的AlCl ₃ /ZSM-5(3T)@γ-Al ₂ O ₃催化剂更有利于再分布反应催化剂。这归因于氯化铝有利改性的鲁棒路易斯位点。

图形摘要

二氯二甲基硅烷在ZSM-5(3 T)@γ-Al ₂ O ₃核壳催化剂和后改性AlCl ₃ /ZSM-5(3 T)@γ-Al ₂ O ₃催化剂上的再分布合成机理通过在 B3LYP/6–311 + + G(3df,2pd) 水平上使用密度泛函理论 (DFT) 方法进行调查。前者活性中心为布朗斯台德酸性中心，后者为路易斯酸性中心，归因于氯化铝有利改性的路易斯位点。合成后的AlCl ₃ /ZSM-5(3 T)@γ-Al ₂ O ₃催化剂的催化活性与实验结果完全一致。