Direct observation of methylcyclopentenyl cations (MCP + ) and olefin generation in methanol conversion over TON zeolite
Direct observation of methylcyclopentenyl cations (MCP + ) and olefin generation in methanol conversion over TON zeolite
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DOI：
10.1039/c5cy01420d
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发表时间：
2016
影响因子：
5
通讯作者：
Jinbang Wang;Yingxu Wei;Jinzhe Li;Shutao Xu;Wenna Zhang;Yanli He;Jingrun Chen;Mozhi Zhang;
中科院分区：
文献类型：
--
作者：
Jinbang Wang;Yingxu Wei;Jinzhe Li;Shutao Xu;Wenna Zhang;Yanli He;Jingrun Chen;Mozhi Zhang;
在250~350℃温度范围内，研究了甲醇在无孔洞、无孔道交叉的沸石H-ZSM-22上的反应机理，首次直接观察到低温甲醇转化的诱导期及在此期间生成的甲基环戊烯基阳离子(MCP+)。用~(13)C幻角旋转(MAS)核磁共振、~(13)C标记实验和理论计算确定了300℃下甲醇转化过程中重要的活性中间体。对不同温度下的反应进行了比较研究，揭示了甲醇转化成烯烃的反应路线和H-ZSM-22催化剂失活方式的差异。
The mechanism of the methanol to olefin (MTO) reaction over H-ZSM-22, a TON-type zeolite without cavities or channel intersections, has been investigated in the temperature range of 250–350 °C. For the first time, an induction period in low-temperature methanol conversion and the methylcyclopentenyl cation (MCP+) formed during this period have been observed directly and successfully. 13C magic angle spinning (MAS) NMR, 13C-labeling experiments and theoretical calculations have been employed to confirm the important active intermediates during methanol conversion at 300 °C. The reactions performed at different temperatures were comparatively studied and the differences in the reaction route for alkene formation from methanol conversion and the modes of H-ZSM-22 catalyst deactivation were revealed.