SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2022, Vol. 47 ›› Issue (7): 174-184.DOI: 10.1016/j.cjche.2021.08.005

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Insights into the confinement effect on isobutane alkylation with C4 olefin catalyzed by zeolite catalyst: A combined theoretical and experimental study

Shuo Li1, Jianlin Cao2, Xiang Feng2, Yupeng Du1, De Chen3, Chaohe Yang2, Wenhua Wang1, Wanzhong Ren1   

  1. 1. College of Chemistry & Chemical Engineering, Yantai University, Yantai 264005, China;
    2. State Key Laboratory of Heavy Oil Processing, School of Chemical Engineering, China University of Petroleum, Qingdao 266580, China;
    3. Department of Chemical Engineering, Norwegian University of Science and Technology, Trondheim 7491, Norway
  • Received:2021-04-13 Revised:2021-08-06 Online:2022-08-19 Published:2022-07-28
  • Contact: Xiang Feng,E-mail:xiangfeng@upc.edu.cn;Chaohe Yang,E-mail:yangch@upc.edu.cn
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (21978325, 21776312, 21908186), the Independent Innovation Foundation of Qingdao (17-1-1-18-jch), the Fundamental Research Funds for the Central Universities (18CX02014A), and the Fundamental Research Funds for the Central Universities and the Opening Fund of State Key Laboratory of Heavy Oil Processing (SKLOP202003002).

Insights into the confinement effect on isobutane alkylation with C4 olefin catalyzed by zeolite catalyst: A combined theoretical and experimental study

Shuo Li1, Jianlin Cao2, Xiang Feng2, Yupeng Du1, De Chen3, Chaohe Yang2, Wenhua Wang1, Wanzhong Ren1   

  1. 1. College of Chemistry & Chemical Engineering, Yantai University, Yantai 264005, China;
    2. State Key Laboratory of Heavy Oil Processing, School of Chemical Engineering, China University of Petroleum, Qingdao 266580, China;
    3. Department of Chemical Engineering, Norwegian University of Science and Technology, Trondheim 7491, Norway
  • 通讯作者: Xiang Feng,E-mail:xiangfeng@upc.edu.cn;Chaohe Yang,E-mail:yangch@upc.edu.cn
  • 基金资助:
    This work was supported by the National Natural Science Foundation of China (21978325, 21776312, 21908186), the Independent Innovation Foundation of Qingdao (17-1-1-18-jch), the Fundamental Research Funds for the Central Universities (18CX02014A), and the Fundamental Research Funds for the Central Universities and the Opening Fund of State Key Laboratory of Heavy Oil Processing (SKLOP202003002).

Abstract: Elucidating the confinement effect harbours tremendous significance for isobutane alkylation with C4 olefin. Herein, the confinement effect over zeolite catalysts was elucidated by combining DFT calculations, experiments (using the novel Beta zeolite exposing only external surfaces (Beta-E) and conventional Beta-I zeolite with both external and internal surfaces) and multi-techniques (e.g., TGA-DTG, HRTEM, SEM and XRD). It is found that the main active sites for C4 alkylation reaction are located on internal surface rather than external surface. On the external surface, the hydride transfer reaction does not occur because the H-shared intermediate cannot be formed without the confinement effect. Moreover, the external surface has stronger selectivity for C4 olefin adsorption than isobutane, leading to enhanced oligomerization reactions. Therefore, the suitable micropore with confinement effect is essential for zeolite-catalyzed C4 alkylation. The atomic-scale insights of this work are of great referential importance to the design of highly effective zeolite catalyst.

Key words: C4 alkylation, Surface, Zeolite, Catalysis, DFT calculation

摘要: Elucidating the confinement effect harbours tremendous significance for isobutane alkylation with C4 olefin. Herein, the confinement effect over zeolite catalysts was elucidated by combining DFT calculations, experiments (using the novel Beta zeolite exposing only external surfaces (Beta-E) and conventional Beta-I zeolite with both external and internal surfaces) and multi-techniques (e.g., TGA-DTG, HRTEM, SEM and XRD). It is found that the main active sites for C4 alkylation reaction are located on internal surface rather than external surface. On the external surface, the hydride transfer reaction does not occur because the H-shared intermediate cannot be formed without the confinement effect. Moreover, the external surface has stronger selectivity for C4 olefin adsorption than isobutane, leading to enhanced oligomerization reactions. Therefore, the suitable micropore with confinement effect is essential for zeolite-catalyzed C4 alkylation. The atomic-scale insights of this work are of great referential importance to the design of highly effective zeolite catalyst.

关键词: C4 alkylation, Surface, Zeolite, Catalysis, DFT calculation