物理化学学报 >> 2017, Vol. 33 >> Issue (11): 22192219-2226.doi: 10.3866/PKU.WHXB201705192

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菱形石墨炔薄膜He分离特性的密度泛函理论研究

李桂霞1,姜永超1,*(),李鹏1,潘维2,李永平1,*(),刘云杰3   

  1. 1 青岛农业大学理学与信息科学学院,山东青岛266109
    2 青岛农业大学化学与药学院,山东青岛266109
    3 中国石油大学(华东)理学院,山东青岛266580
  • 收稿日期:2017-04-12 发布日期:2017-08-25
  • 通讯作者: 姜永超,李永平 E-mail:qdycjiang@126.com;qdyongpli@126.com
  • 基金资助:
    山东省重点研发项目(2015GGB01552)

Helium Separation Performance of the Rhombic-Graphyne Monolayer Membrane: Density Functional Theory Calculations

Gui-Xia LI1,Yong-Chao JIANG1,*(),Peng LI1,Wei PAN2,Yong-Ping LI1,*(),Yun-Jie LIU3   

  1. 1 College of Science and Information, Qingdao Agricultural University, Qingdao 266109, Shandong Province, P. R. China
    2 College of Chemistry and Pharmaceutical Sciences, Qingdao Agricultural University, Qingdao 266109, Shandong Province, P. R. China
    3 College of Science, China University of Petroleum, Qingdao 266580, Shandong Province, P. R. China
  • Received:2017-04-12 Published:2017-08-25
  • Contact: Yong-Chao JIANG,Yong-Ping LI E-mail:qdycjiang@126.com;qdyongpli@126.com
  • Supported by:
    Shandong Province Key Research and Development Projects, China(2015GGB01552)

摘要:

氦气在科学和工业等领域中都具有不可替代的作用,其主要存在于天然气中。如何高效地从天然气中分离氦气显得至关重要。本文基于密度泛函理论(DFT)方法系统地探究了菱形石墨炔(rhombic-graphyne,R-GY)分离膜对He和其他天然气组分(Ne、Ar、CO2、N2和CH4)的吸附、选择和渗透性能。结果表明,R-GY作为He分离膜可同时满足高选择性和高渗透率的要求。常温下,R-GY薄膜对He/Ne、He/CO2、He/N2、He/Ar和He/CH4的选择性可分别达到2×107、3×1020、9×1026、7×1037和5×1051,即使在600 K时仍可保持较高水平。此外,由于较低的扩散能垒,He穿透R-GY薄膜的渗透率在常温下可达到10-6 mol·m-2·s-1·Pa-1,高出工业标准近3个数量级;而其他气体组分在常温下的渗透率仅为10-58-10-14 mol·m-2·s-1·Pa-1,气体无法渗透R-GY薄膜。

关键词: 菱形石墨炔, He分离, 选择性, 渗透率, 密度泛函理论

Abstract:

Helium, which primarily occurs as a component of natural gas, has an irreplaceable role in both scientific and industrial fields. Therefore, it is crucial to separate helium from natural gas efficiently. Using density functional theory (DFT), we systematically investigate the adsorption, selectivity, and permeability characteristics of the rhombic-graphyne (R-GY) monolayer membrane for He and other components of natural gas (Ne, Ar, CO2, N2, and CH4). These results demonstrate that the R-GY monolayer can fulfill the requirements of both high selectivity and high permeance as a membrane for He separation. At 300 K, the He selectivities of the R-GY membrane can be up to 2×107, 3×1020, 9×1026, 7×1037, and 5×1051 over Ne, CO2, N2, Ar, and CH4, respectively. The membrane can maintain high selectivity even at 600 K. In addition, the He permeance of R-GY at room temperature can reach 10-6 mol·m-2·s-1·Pa-1, which is higher than the industrial standard by about three orders of magnitude, because of its low diffusion energy barrier. In contrast, the permeance of the other gas components is only 10-58-10-14 mol·m-2·s-1·Pa-1 at room temperature, indicating the impermeability of the R-GY to these components.

Key words: Rhombic-graphyne, He separation, Selectivity, Permeance, Density functional theory

MSC2000: 

  • O647