1. Modulating acid site spatial location of Zn/ZSM‐5 catalyst to boost the stable aromatization of hexane.
- Author
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Yan, Hao, Ren, Delun, Li, Zhiqiang, Chen, Junshu, Zhang, Xinyang, Wang, Yanhao, Duan, Gongzheng, Feng, Xiang, Zhou, Xin, Liu, Yibin, Chen, Xiaobo, and Yang, Chaohe
- Subjects
AROMATIZATION catalysts ,AROMATIZATION ,ZEOLITE catalysts ,HEXANE ,CATALYSTS ,ACID catalysts ,ZEOLITES - Abstract
Engineering acid site spatial location of zeolite catalyst harbors tremendous potential to boost catalytic performance but still remains a grand challenge for aromatization reaction. Herein, we successfully manipulate acid site spatial location inside the ZSM‐5 channels to promote the hexane aromatization via the simple SiO2 coating treatment. Multi‐techniques demonstrated that the medium strong L acid in the channel originated from the Si(Al)OZn structure is mainly retained in the Zn/ZSM‐5‐Si catalyst by covering the acid sites outside the channel. Surprisingly, there is a good linear relationship between BTEX yield and this medium strong L acid content. Based on the reaction kinetics, in situ FT‐IR and theoretical calculations, it is found that the L acid with confinement effect served as the main active site could prominently enhance the cyclization of propene intermediate and the dehydrogenation of cycloalkane due to the strong affinity between the C/H and ZnOx, and control the desorption of BTEX (mainly benzene, toluene, ethylbenzene, and p‐xylene) by weakening the binding of hydrogen proton to π electrons. Compared with the ordinary Zn/ZSM‐5 catalyst, the yield of BTEX is increased by nearly 10%, and the Zn/ZSM‐5‐Si catalyst exhibits excellent anti coking deactivation ability. This strategy together with mechanistic results may pave the rational design of efficient Zn/ZSM‐5 catalysts for aromatization reaction. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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