Methanol Usage in Toluene Methylation with Medium and Large Pore Zeolites
Methanol Usage in Toluene Methylation with Medium and Large Pore Zeolites
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DOI：
10.1021/cs4000766
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发表时间：
2013-03
期刊：
影响因子：
12.9
通讯作者：
Johng‐Hwa Ahn;R. Kolvenbach;S. Al-Khattaf;A. Jentys;J. Lercher
中科院分区：
文献类型：
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作者：
Johng‐Hwa Ahn;R. Kolvenbach;S. Al-Khattaf;A. Jentys;J. Lercher
考察了四种不同孔结构的酸性分子筛H-ZSM 5和H-ZSM 11以及大孔分子筛H-MOR和H-MOR对甲苯甲基化反应的影响。测定了甲苯、对二甲苯和1，2，4-三甲基苯与甲醇反应的甲基化速率、甲醇消耗速率、轻烃生成速率和反硝化速率。甲苯甲基化的产物（例如，二甲苯和三甲基苯）在中孔和大孔沸石中都易于进一步甲基化。与大孔沸石相比，使用中孔沸石形成轻质烃的甲醇比例相当高。这与以下事实有关：相对于在较早阶段的甲基化，即在较少的甲基基团被添加到芳环之后，从高度甲基化的芳族化合物中脱烷基化轻质烃变得更有利。用中孔沸石提高大体积芳烃分子的有效停留时间…
The reaction of toluene methylation was investigated with four acidic zeolites of different pore geometries: the medium pore zeolites H-ZSM5 and H-ZSM11 as well as the large pore zeolites H-MOR and H-BEA. The methylation, methanol consumption, light hydrocarbon formation, and disproportionation rates for the reaction of toluene, p-xylene, and 1,2,4-trimethylbenezene with methanol were determined. The products of toluene methylation (e.g., xylenes and trimethylbenzenes) were readily methylated further in both medium and large pore zeolites. A considerably higher fraction of methanol was used to form light hydrocarbons with the medium pore zeolites than with large pore zeolites. This was related to the fact that the dealkylation of light hydrocarbons from highly methylated aromatics became more favorable relative to methylation at an earlier stage, that is, after fewer methyl groups were added to the aromatic ring. Increasing the effective residence time of bulky aromatic molecules with medium pore zeolites...