Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (12): 3305-3309.doi: 10.3866/PKU.WHXB20101228

• CATALYSIS AND SURFACE STRUCTURE • Previous Articles     Next Articles

Deactivation of Ag/ZSM-5 Catalyst in the Aromatization of Methanol

TIAN Tao1,2, QIAN Wei-Zhong1, TANG Xiao-Ping1, YUN Song1, WEI Fei1   

  1. 1. Beijing Key Laboratory of Green Reaction Engineering and Technology, Department of Chemical Engineering, Tsinghua University, Beijing 100084, P. R. China;

    2. Economics & Development Research Institute, SINOPEC, Beijing 100029, P. R. China
  • Received:2010-08-06 Revised:2010-10-15 Published:2010-12-01
  • Contact: QIAN Wei-Zhong E-mail:qianwz@mail.tsinghua.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20736004, 20736007) and Program for New Century Excellent Talents in Universities of the Ministry of Education of China (NECT-07-0489).

Abstract:

The deactivation and regeneration properties of the methanol aromatization catalyst, Ag/ ZSM-5, were investigated by a continuous reaction-catalyst regeneration experiment over four cycles. The activity of the catalyst decreased gradually over the long reaction and was only partly recovered after coke burning. Characterization of the regenerated catalyst by X-ray diffraction (XRD) and transmission electron microscope (TEM) revealed that the ZSM-5 framework remained unchanged and that the sintering of the Ag nanoparticles was not serious. Analyses by Fourier transform Infrared spectroscopy (FTIR) and ammonia-temperature programmed desorption (NH3-TPD) experiment confirmed that the hydrothermal de-alumination of the catalyst by water in large amounts at 475 °C during aromatization resulted in a significant loss of Brønsted acidity. Consequently, an irreversible decrease in the aromatization ability of the catalyst was apparent.

Key words: Methanol, Aromatization, Ag/ZSM-5, Deactivation, Regeneration

MSC2000: 

  • O643