Bifunctional Catalysts for One-Step Conversion of Syngas into Aromatics with Excellent Selectivity and Stability
Bifunctional Catalysts for One-Step Conversion of Syngas into Aromatics with Excellent Selectivity and Stability
复制标题
用于合成气一步转化为芳烃的双功能催化剂，具有优异的选择性和稳定性
DOI：
10.1016/j.chempr.2017.05.007
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发表时间：
2017-08-10
期刊：
影响因子：
23.5
通讯作者：
Wang, Ye
中科院分区：
文献类型：
--
作者：
Cheng, Kang;Zhou, Wei;Wang, Ye
合成气(CO/H-2)是化学利用非石油碳资源的重要平台。在合成气转化路线中，芳烃的直接合成是最重要的大宗化学品之一，由于选择性有限和催化剂稳定性差，直接合成芳烃的成功较少。在H-ZSM-5分子筛上成功地设计了双功能催化剂，用于合成气一步转化制芳烃反应，具有高选择性和高稳定性。在CO转化率为20%时，芳烃选择性为80%，在1000小时内无催化剂失活现象。在掺锌的氧化锌催化剂上，甲醇和二甲醚是主要的中间体，这些中间体在H-ZSM-5上通过烯烃转化为芳烃。发现了CO在芳烃选择性生成中的自促进作用机理。在烯烃脱氢芳构化反应中，CO不仅是一种反应物，而且有利于H-ZSM-5上生成的氢物种的脱除。
Syngas (CO/H-2) is a key platform for chemical utilization of non-petroleum carbon resources. Among syngas transformation routes, the direct synthesis of aromatics, which are among the most important bulk chemicals, is less successful because of the limited selectivity and poor catalyst stability. We report a successful design of bifunctional catalysts composed of Zn-doped ZrO2 nanoparticles dispersed on zeolite H-ZSM-5 for one-step conversion of syngas to aromatics with high selectivity and stability. Aromatics with 80% selectivity at CO conversion of 20% were achieved, and there was no catalyst deactivation in 1,000 hr. Methanol and dimethyl ether were formed as major intermediates on Zn-doped ZrO2, which were subsequently converted into aromatics on H-ZSM-5 via olefins. We discovered a self-promotion mechanism of CO in the selective formation of aromatics. As well as being a reactant, CO facilitates the removal of hydrogen species formed on H-ZSM-5 in the dehydrogenative aromatization of olefins.