Hydrogen transfer versus olefins methylation: On the formation trend of propene in the methanol-to-hydrocarbons reaction over Beta zeolites
Hydrogen transfer versus olefins methylation: On the formation trend of propene in the methanol-to-hydrocarbons reaction over Beta zeolites
复制标题
氢转移与烯烃甲基化：β沸石上甲醇制烃反应中丙烯的形成趋势
DOI：
10.1016/j.jcat.2018.10.015
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发表时间：
2018-12
影响因子：
7.3
通讯作者：
Lei Xu
中科院分区：
文献类型：
--
作者：
Jie Zhang;Lanjian Xu;Yanfei Zhang;Zhihua Huang;Xiaomin Zhang;Xinzhi Zhang;Yangyang Yuan;Lei Xu
制备了具有类似结构性质但不同布朗斯台德酸中心（BAS）密度（25.5-203.8 μmol g− 1）的β沸石，并将其作为甲醇制烃反应的催化剂进行了研究。考察了BAS用量、BAS浓度和甲醇转化率对反应机理的内在影响。有趣的是，甲醇转化率取决于BAS量，而与BAS密度无关。甲醇浓度的增加可以通过促进甲醇诱导的氢转移反应、促进烯烃甲基化反应和抑制高碳烯烃裂解来调节产物分布。随着BAS密度从203.8 μmol g− 1降低到56.6 μmol g−1，氢转移反应逐渐受到抑制，同时烯烃互变增强，导致烯烃基循环逐渐取代芳烃基循环，从而提高丙烯选择性。然而，随着BAS密度从56.6 μmol g−1进一步降低，丙烯选择性下降，因为烯烃基循环中的甲基化途径比裂解途径更有利。在详细研究了所涉及的Beta沸石的失活行为之后，已经发现长链烷烃和大的多环芳烃的积累是导致催化剂失活的原因。这些结果提供了进一步了解BAS密度对反应机理和产物选择性的影响。
Beta zeolites with similar textural properties but variable Brønsted acid site (BAS) densities in the range of 25.5–203.8 μmol g−1were fabricated and investigated as catalysts in the methanol-to-hydrocarbons reaction. The intrinsic influence of BAS amount, BAS density and methanol conversion on the reaction mechanism was investigated. Interestingly, methanol conversion depends on the BAS amount regardless of the BAS density. The increase of methanol concentration could modulate the product distribution by promoting the methanol-induced hydrogen transfer reaction and enhancing the olefins methylation as well as inhibiting the cracking of higher olefins. As the BAS density decreases from 203.8 to 56.6 μmol g−1, hydrogen transfer reaction is gradually restrained while the olefin interconversion is enhanced, leading to gradual replacement of aromatics-based cycle by the olefins-based cycle and thus increasing the propene selectivity. However, as BAS density further decreases from 56.6 μmol g−1, the propene selectivity declines because the methylation route in the olefins-based cycle is much more favoured than the cracking route. After detailed investigation of the deactivation behaviours of involved Beta zeolites, it has been found that the accumulation of long-chain alkanes and large polycyclic aromatics is responsible for the catalyst deactivation. These results provide further insights into the effect of BAS density on the reaction mechanism and product selectivity.
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影响因子：
1.4
作者：
S. Khadzhiev;M. Magomedova;E. V. Peresypkina
通讯作者：
S. Khadzhiev;M. Magomedova;E. V. Peresypkina
甲醇制丙烯：磷对高硅 HZSM-5 催化剂的影响
影响因子：
3.7
作者：
Shen, Wei;Hua, Weiming;Yue, Yinghong;Xu, Hualong;Liu, Jian;Shen, Zhenhao;Zhang, Chenxi;Tang, Yi
通讯作者：
Tang, Yi
影响因子：
3.3
作者：
Haw, JF
通讯作者：
Haw, JF
影响因子：
7.3
作者：
J. Meusinger;A. Corma
通讯作者：
J. Meusinger;A. Corma
影响因子：
16.5
作者：
Mozhi Zhang;Shutao Xu;Yingxu Wei;Jinzhe Li;Jinbang Wang;Wenna Zhang;Shushu Gao;Zhongmin Liu
通讯作者：
Mozhi Zhang;Shutao Xu;Yingxu Wei;Jinzhe Li;Jinbang Wang;Wenna Zhang;Shushu Gao;Zhongmin Liu