Chem. J. Chinese Universities ›› 2022, Vol. 43 ›› Issue (8): 20220090.doi: 10.7503/cjcu20220090

• Physical Chemistry • Previous Articles     Next Articles

Preparation of Hierarchical Microporous-mesoporous Fe2O3/ZSM-5 Hollow Molecular Sieve Catalytic Materials and Their Catalytic Properties for Benzylation

YAO Yiting1, LYU Jiamin1, YU Shen1, LIU Zhan1, LI Yu1, LI Xiaoyun2(), SU Baolian1, CHEN Lihua1()   

  1. 1.State Key Laboratory of Advanced Technology for Materials Synthesis and Processing
    2.State Key Laboratory of Silicate Materials for Architecture,Wuhan University of Technology,Wuhan 430070,China
    3.Laboratory of Inorganic Materials Chemistry,University of Namur,Namur B? 5000,Belgium
  • Received:2022-02-12 Online:2022-08-10 Published:2022-04-28
  • Contact: LI Xiaoyun,CHEN Lihua E-mail:xiaoyunli2015@whut.edu.cn;chenlihua@whut.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(U20A20122)

Abstract:

As a kind of efficient and environment friendly solid catalyst, ZSM-5 zeolite shows extremely uniform pore structure, excellent shape selectivity, great catalytic activity and superb hydrothermal stability, which has already been used in plenty of fields like petroleum catalytic cracking, fine-chemicals processing and environmental protection. However, its simplex microporous structure severely reduces the diffusion of guest molecules, which results in a great limitation of aromatic alkylation reaction in which macromolecules participate. In this paper, through a method of etching ZSM-5 zeolite with NaOH/TPAOH(tetrapropylammonium hydroxide) mixed alkali, a hierarchical micro-/mesoporous ZSM-5 catalyst with high crystallinity and abundant specific surface area was prepared. This special hierarchical structure can not only maintain the great hydrothermal stability and plentiful active centers of microporous ZSM-5, but also promote the diffusion of reactants and products with the introduction of mesopores. As a result, the conversion of m-trimethylbenzene benzylation increased 3.8 times. In addition, a bifunctional hierarchical micro-/mesoporous Fe2O3/ZSM-5 hollow catalyst was developed by loading Fe on the hierarchical microporous- mesoporous ZSM-5 hollow catalyst mentioned above, which exhibited excellent catalytic performance in the benzylation reaction of benzene, and the conversion, selectivity and percent yield reached 98.3%, 81.6% and 80.2% while Fe loading was 6.67%(mass fraction), and the reaction temperature and the reaction time were 75 ℃ and 15 min, respectively.

Key words: Hierarchically porous zeolite, Alkali treatment, Fe2O3/ZSM-5, Benzylation reaction

CLC Number: 

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