SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2018, Vol. 26 ›› Issue (3): 545-550.DOI: 10.1016/j.cjche.2017.11.009

• Catalysis, Kinetics and Reaction Engineering • 上一篇    下一篇

Dealumination kinetics of composite ZSM-5/mordenite zeolite during steam treatment: An in-situ DRIFTS study

Xiaoxiao Zhang, Dangguo Cheng, Fengqiu Chen, Xiaoli Zhan   

  1. Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
  • 收稿日期:2017-05-25 修回日期:2017-11-13 出版日期:2018-03-28 发布日期:2018-04-18
  • 通讯作者: Dangguo Cheng
  • 基金资助:

    Supported by the National Key Research and Development Program of China (2016YFA0202900), the National Natural Science Foundation of China (91434123, 21622606), Zhejiang Provincial Natural Science Foundation of China (LR18B060001) and the Fundamental Research Funds for the Central Universities.

Dealumination kinetics of composite ZSM-5/mordenite zeolite during steam treatment: An in-situ DRIFTS study

Xiaoxiao Zhang, Dangguo Cheng, Fengqiu Chen, Xiaoli Zhan   

  1. Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
  • Received:2017-05-25 Revised:2017-11-13 Online:2018-03-28 Published:2018-04-18
  • Contact: Dangguo Cheng
  • Supported by:

    Supported by the National Key Research and Development Program of China (2016YFA0202900), the National Natural Science Foundation of China (91434123, 21622606), Zhejiang Provincial Natural Science Foundation of China (LR18B060001) and the Fundamental Research Funds for the Central Universities.

摘要: To get a better understanding of structural deactivation of ZSM-5/MOR during the catalytic cracking of n-heptane in the steam atmosphere, a comprehensive mechanism of hydrothermal dealumination was proposed through in-situ diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) in this work. The mechanism can be divided into two steps:firstly, the hydrolysis of four Al-O bonds, and secondly, the self-healing of Si-OH bonds accompanied with partial condensation of the extra-framework Al species. Accordingly, the kinetics of dealumination process has also been fully discussed. In the IR spectra, the range of 3450-3850 cm-1 could be deconvolved to distinguish the hydroxyl groups on the different position and calculate the consumption of each hydroxyl group during the reaction. Based on results from the in-situ DRIFTS, the kinetics of dealumination was hence developed and also in well agreement with the kinetics of deactivation of ZSM/MOR catalysts during the reaction in the presence of little coke deposits.

关键词: Zeolite, Dealumination, Kinetics, Hydrothermal treatment

Abstract: To get a better understanding of structural deactivation of ZSM-5/MOR during the catalytic cracking of n-heptane in the steam atmosphere, a comprehensive mechanism of hydrothermal dealumination was proposed through in-situ diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) in this work. The mechanism can be divided into two steps:firstly, the hydrolysis of four Al-O bonds, and secondly, the self-healing of Si-OH bonds accompanied with partial condensation of the extra-framework Al species. Accordingly, the kinetics of dealumination process has also been fully discussed. In the IR spectra, the range of 3450-3850 cm-1 could be deconvolved to distinguish the hydroxyl groups on the different position and calculate the consumption of each hydroxyl group during the reaction. Based on results from the in-situ DRIFTS, the kinetics of dealumination was hence developed and also in well agreement with the kinetics of deactivation of ZSM/MOR catalysts during the reaction in the presence of little coke deposits.

Key words: Zeolite, Dealumination, Kinetics, Hydrothermal treatment