能源化学(英文) ›› 2013, Vol. 22 ›› Issue (5): 769-777.

• ARTICLES • 上一篇    下一篇

Catalytic performance of hierarchical H-ZSM-5/MCM-41 for methanol dehydration to dimethyl ether

Yu Sang, Hongxiao Liu, Shichao He, Hansheng Li, Qingze Jiao, Qin Wu, Kening Sun   

  1. School of Chemical Engineering and the Environment, Beijing Institute of Technology, Beijing 100081, China
  • 收稿日期:2013-01-03 修回日期:2013-02-22 出版日期:2013-09-20 发布日期:2013-09-30
  • 通讯作者: Hansheng Li

Catalytic performance of hierarchical H-ZSM-5/MCM-41 for methanol dehydration to dimethyl ether

Yu Sang, Hongxiao Liu, Shichao He, Hansheng Li, Qingze Jiao, Qin Wu, Kening Sun   

  1. School of Chemical Engineering and the Environment, Beijing Institute of Technology, Beijing 100081, China
  • Received:2013-01-03 Revised:2013-02-22 Online:2013-09-20 Published:2013-09-30

摘要: Micro-mesoporous composite molecular sieves H-ZSM-5/MCM-41 were prepared by the hydrothermal technique with alkali-treated H-ZSM-5 zeolite as the source and characterized by scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, X-ray diffraction, N2 adsorption-desorption measurement and NH3 temperature-programmed desorption. The catalytic performances for the methanol dehydration to dimethyl ether over H-ZSM-5/MCM-41 were evaluated. Among these catalysts, H-ZSM-5/MCM-41 prepared with NaOH dosage (nNa/nSi) varying from 0.4 to 0.47 presented excellent catalytic activity with more than 80% methanol conversion and 100% dimethyl ether selectivity in a wide temperature range of 170-300℃, and H-ZSM-5/MCM-41 prepared with nNa/nSi=0.47 showed constant methanol conversion of about 88.7%, 100% dimethyl ether selectivity and excellent lifetime at 220℃. The excellent catalytic performances were due to the highly active and uniform acidic sites and the hierarchical porosity in the micro-mesoporous composite molecular sieves. The catalytic mechanism of H-ZSM-5/MCM-41 for the methanol dehydration to dimethyl ether process was also discussed.

关键词: hierarchical porosity, H-ZSM-5, composite molecular sieve, methanol dehydration, dimethyl ether

Abstract: Micro-mesoporous composite molecular sieves H-ZSM-5/MCM-41 were prepared by the hydrothermal technique with alkali-treated H-ZSM-5 zeolite as the source and characterized by scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, X-ray diffraction, N2 adsorption-desorption measurement and NH3 temperature-programmed desorption. The catalytic performances for the methanol dehydration to dimethyl ether over H-ZSM-5/MCM-41 were evaluated. Among these catalysts, H-ZSM-5/MCM-41 prepared with NaOH dosage (nNa/nSi) varying from 0.4 to 0.47 presented excellent catalytic activity with more than 80% methanol conversion and 100% dimethyl ether selectivity in a wide temperature range of 170-300℃, and H-ZSM-5/MCM-41 prepared with nNa/nSi=0.47 showed constant methanol conversion of about 88.7%, 100% dimethyl ether selectivity and excellent lifetime at 220℃. The excellent catalytic performances were due to the highly active and uniform acidic sites and the hierarchical porosity in the micro-mesoporous composite molecular sieves. The catalytic mechanism of H-ZSM-5/MCM-41 for the methanol dehydration to dimethyl ether process was also discussed.

Key words: hierarchical porosity, H-ZSM-5, composite molecular sieve, methanol dehydration, dimethyl ether