Insight into the effect of incorporation of boron into ZSM-11 on its catalytic performance for conversion of methanol to olefins
Insight into the effect of incorporation of boron into ZSM-11 on its catalytic performance for conversion of methanol to olefins
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深入探讨ZSM-11中掺入硼对其甲醇转化为烯烃催化性能的影响
DOI：
10.1039/c7cy01428g
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发表时间：
2017
影响因子：
5
通讯作者：
Fan Weibin
中科院分区：
文献类型：
--
作者：
Wang Sen;Li Shiying;Zhang Li;Qin Zhangfeng;Dong Mei;Li Junfen;Wang Jianguo;Fan Weibin
通过在合成凝胶中添加不同量的硼，合成了一系列ZSM-11分子筛，以提高其甲醇转化制烯烃（MTO）的催化性能。结果表明，硼对ZSM-11的晶体结构、织构性质和酸中心强度影响不大，但能显著提高其催化稳定性和氢化物转移活性，导致产物中芳烃和烷烃的含量增加。DFT计算表明，铝和硼原子竞争进入ZSM-11骨架。结合~（27）Al MAS NMR、GC-MS、间二甲苯异构化和Co2+交换ZSM-11漫反射紫外-可见光谱的结果，可以推断硼的引入迫使一些铝原子向交叉T位移动，这可以大大缓解结焦过程，尽管它允许形成更大的分子。这表明ZSM-11的MTO催化性能可以通过调节骨架中铝或酸位点位置来改变引入的硼的量而在很大程度上调节。
A series of ZSM-11 zeolites was synthesized by adding different amounts of boron to a synthesis gel for the purpose of improving its catalytic performance for conversion of methanol to olefins (MTO). It was found that boron has marginal effects on the crystal structure, texture properties and acid site strength of ZSM-11, but it significantly increases its catalytic stability and hydride transfer activity that results in an increase in the amounts of aromatics and alkanes in products. DFT calculations revealed that aluminum and boron atoms competitively enter the ZSM-11 framework. In combination with 27Al MAS NMR, GC-MS, m-xylene isomerization and Co2+-exchanged ZSM-11 diffuse reflectance UV-vis spectroscopy results, it can be deduced that incorporation of boron compels some aluminum atoms to shift towards the intersection T sites, which can greatly alleviate the coking process although it allows the formation of more bulky molecules. This shows that the MTO catalytic performance of ZSM-11 can be largely adjusted by changing the amount of incorporated boron through regulation of aluminum or acid site locations in the framework.