Mechanism of olefin synthesis from methanol and dimethyl ether over zeolite catalysts: A review
Mechanism of olefin synthesis from methanol and dimethyl ether over zeolite catalysts: A review
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DOI：
10.1134/s0965544114040057
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发表时间：
2014-07
影响因子：
1.4
通讯作者：
S. Khadzhiev;M. Magomedova;E. V. Peresypkina
中科院分区：
文献类型：
--
作者：
S. Khadzhiev;M. Magomedova;E. V. Peresypkina
本文综述了分子筛催化剂上甲醇和二甲醚转化过程中第一碳碳键和低碳烯烃的形成机理。该反应通常使用连续和平行机制来描述。根据第一个概念，氧鎓叶立德，卡宾，碳阳离子，甲烷-甲醛，和自由基的机制进行了分析。C-C键的平行形成被表示为"烃池"机制，其假设反应通过烯烃和芳烃循环发生。结果表明，在芳烃环中，由于多甲苯侧链的增长（所谓侧链机理）或由于芳环中碳原子数的减少（配对机理），可以生成烯烃。沿着异构化和同步化机理，认为反应路线主要由反应温度和催化剂性质决定。
This review presents various first C-C bond and lower olefins formation mechanisms during the conversion of methanol or dimethyl ether (DME) over zeolite catalysts. The reaction is commonly described using both consecutive and parallel mechanisms. In terms of the first one concept, the oxonium ylide, carbene, carbocationic, methane-formaldehyde, and free radical mechanisms are analyzed. The parallel formation of the C-C bond is represented as the “hydrocarbon pool” mechanism which assumes the reaction occurs through alkene and arene cycles. It is shown that in the case of the arene cycle, olefins can be formed owing to the side chain growth of polymethylbenzenes (the so-calledside-chainmechanism) or owing to the number of carbon atoms decrease in the aromatic ring (paringmechanism). Along with the isomerization and synchronous mechanisms wich assume that the route of the process substantially determined by the temperature range and the catalysts properties are discussed.