SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2020, Vol. 28 ›› Issue (7): 1898-1903.DOI: 10.1016/j.cjche.2020.05.024

• Chemical Engineering Thermodynamics • 上一篇    下一篇

Strain-controlled graphdiyne membrane for CO2/CH4 separation: Firstprinciple and molecular dynamic simulation

Xin Zheng1, Shuai Ban1,2, Bei Liu1, Guangjin Chen1   

  1. 1 State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China;
    2 College of New Energy and Materials, China University of Petroleum, Beijing 102249, China
  • 收稿日期:2020-02-07 修回日期:2020-04-16 出版日期:2020-07-28 发布日期:2020-08-31
  • 通讯作者: Shuai Ban, Bei Liu
  • 基金资助:
    The financial support received from the National Natural Science Foundation of China (21776301) and the Science Foundation of China University of Petroleum, Beijing (2462018BJC004) are gratefully acknowledged.

Strain-controlled graphdiyne membrane for CO2/CH4 separation: Firstprinciple and molecular dynamic simulation

Xin Zheng1, Shuai Ban1,2, Bei Liu1, Guangjin Chen1   

  1. 1 State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, China;
    2 College of New Energy and Materials, China University of Petroleum, Beijing 102249, China
  • Received:2020-02-07 Revised:2020-04-16 Online:2020-07-28 Published:2020-08-31
  • Contact: Shuai Ban, Bei Liu
  • Supported by:
    The financial support received from the National Natural Science Foundation of China (21776301) and the Science Foundation of China University of Petroleum, Beijing (2462018BJC004) are gratefully acknowledged.

摘要: Tensile strain of porous membrane materials can broaden their capacity in gas separation. In this work, using van der Waals corrected density functional theory (DFT) and molecular dynamics (MD) simulations, the performance and mechanism of CO2/CH4 separation through strain-oriented graphdiyne (GDY) monolayer were studied by applying lateral strain. It is demonstrated that the CO2 permeance peaks at 1.29×106 gas permeation units (GPU) accompanied with CO2/CH4 selectivity of 5.27×103 under ultimate strain, both of which are far beyond the Robeson's limit. Furthermore, the GDY membrane exhibited a decreasing gas diffusion energy barrier and increasing permeance with the increase of applied tensile strain. CO2 molecule tends to reoriented itself vertically to permeate the membrane. Finally, the CO2 permeability decreases with the increase of the temperature from 300 K to 500 K due to conserving of rotational freedom, suggesting an abnormal permeance of CO2 in relation to temperature. Our theoretical results suggest that the stretchable GDY monolayer holds great promise to be an excellent candidate for CO2/CH4 separation, owing to its extremely high selectivity and permeability of CO2.

关键词: Graphdiyne, Strain, CO2 separation, Molecular dynamics, Density functional theory

Abstract: Tensile strain of porous membrane materials can broaden their capacity in gas separation. In this work, using van der Waals corrected density functional theory (DFT) and molecular dynamics (MD) simulations, the performance and mechanism of CO2/CH4 separation through strain-oriented graphdiyne (GDY) monolayer were studied by applying lateral strain. It is demonstrated that the CO2 permeance peaks at 1.29×106 gas permeation units (GPU) accompanied with CO2/CH4 selectivity of 5.27×103 under ultimate strain, both of which are far beyond the Robeson's limit. Furthermore, the GDY membrane exhibited a decreasing gas diffusion energy barrier and increasing permeance with the increase of applied tensile strain. CO2 molecule tends to reoriented itself vertically to permeate the membrane. Finally, the CO2 permeability decreases with the increase of the temperature from 300 K to 500 K due to conserving of rotational freedom, suggesting an abnormal permeance of CO2 in relation to temperature. Our theoretical results suggest that the stretchable GDY monolayer holds great promise to be an excellent candidate for CO2/CH4 separation, owing to its extremely high selectivity and permeability of CO2.

Key words: Graphdiyne, Strain, CO2 separation, Molecular dynamics, Density functional theory