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乙烷在单壁碳纳米管中的密度泛函理论研究

张现仁   

  1. Key Laboratory of Science and Technology of Controllable Chemical Reactions of Education
    Ministry, Beijing University of Chemical Technology, Beijing 100029, China
  • 收稿日期:1900-01-01 修回日期:1900-01-01 出版日期:2002-12-28 发布日期:2002-12-28
  • 通讯作者: 张现仁

Ethane Adsorption in Single Walled Carbon Nanotube by Density Functional Theory

ZHANG Xianren   

  1. Key Laboratory of Science and Technology of Controllable Chemical Reactions of Education
    Ministry, Beijing University of Chemical Technology, Beijing 100029, China
  • Received:1900-01-01 Revised:1900-01-01 Online:2002-12-28 Published:2002-12-28
  • Contact: ZHANG Xianren

摘要: Density functional theory (DFT) is used to calculate adsorption of ethane molecules in
single walled carbon nanotubes. A compari-son of DFT calculations and grand canonical
ensemble Monte Carlo (GCMC) simulations is made first and the two methods are in good
agree-ment. Adsorption isotherms and structures of ethane molecules inside the tubes have
been studied by DFT for the nanotubes of diameters 0.954,2.719 and 4.077 nm at 157 K and
ambient temperature, 300 K. By using the grand potential, the positions of phase
transitions are exactly lo-cated, and the effect of temperature and tube diameter on phase
transitions and adsorption is discussed. We found that lowering temperature andincreasing
the pore size of several nanometer is preferable for the ethane adsorption when temperature
is in the range of 157 K-300 K and op-erating pressure reaches several MPa. Layering
transitions and capillary condensations are observed at 157 K in two larger pore
diameters,while these phase transitions disappear or the hysteres is loops become very
narrow at 300 K.

关键词: density functional theory;adsorption;ethane;single walled carbon nanotube

Abstract: Density functional theory (DFT) is used to calculate adsorption of ethane molecules in
single walled carbon nanotubes. A compari-son of DFT calculations and grand canonical
ensemble Monte Carlo (GCMC) simulations is made first and the two methods are in good
agree-ment. Adsorption isotherms and structures of ethane molecules inside the tubes have
been studied by DFT for the nanotubes of diameters 0.954,2.719 and 4.077 nm at 157 K and
ambient temperature, 300 K. By using the grand potential, the positions of phase
transitions are exactly lo-cated, and the effect of temperature and tube diameter on phase
transitions and adsorption is discussed. We found that lowering temperature andincreasing
the pore size of several nanometer is preferable for the ethane adsorption when temperature
is in the range of 157 K-300 K and op-erating pressure reaches several MPa. Layering
transitions and capillary condensations are observed at 157 K in two larger pore
diameters,while these phase transitions disappear or the hysteres is loops become very
narrow at 300 K.

Key words: density functional theory, adsorption, ethane, single walled carbon nanotube