Yang Qingyuan, Zhong Chongli
Laboratory of Computational Chemistry, Department of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
Langmuir. 2009 Feb 17;25(4):2302-8. doi: 10.1021/la8035902.
In this work, grand canonical Monte Carlo simulations were performed to investigate the adsorption behaviors of three important gases (CO2, CH4 and H2) in two two-dimensional (2D) covalent organic frameworks (COFs) with different pore sizes. The simulation results show that stepped behavior is common in gas adsorption in 2D COFs, and multilayer formation is likely to be the underlying mechanism. For CO2 adsorption in 2D COFs, stepped phenomena easily occur, and the electrostatic interactions between CO2-CO2 molecules play a dominant role, while, within the temperature range studied, no stepped behaviors were found in isotherms for H2 adsorption in 2D COFs because of the too weak interactions in the systems. In addition, this work demonstrates that the stepped behaviors are highly affected by temperature, pore size, and the interaction strengths between adsorbates as well as those between adsorbates and adsorbents.
在这项工作中，进行了巨正则蒙特卡罗模拟，以研究三种重要气体（二氧化碳、甲烷和氢气）在两种具有不同孔径的二维共价有机框架（COF）中的吸附行为。模拟结果表明，阶梯状行为在二维COF的气体吸附中很常见，多层形成可能是其潜在机制。对于二维COF中的二氧化碳吸附，容易出现阶梯状现象，且二氧化碳分子之间的静电相互作用起主导作用，而在所研究的温度范围内，二维COF中氢气吸附的等温线未发现阶梯状行为，因为体系中的相互作用太弱。此外，这项工作表明，阶梯状行为受温度、孔径、吸附质之间以及吸附质与吸附剂之间的相互作用强度的影响很大。
