Khalili Azita Amouzad, Yeganegi Saeid
Department of Physical Chemistry, Faculty of Chemistry, University of Mazandaran, Babolsar, 47416-95447, Iran.
Department of Physical Chemistry, Faculty of Chemistry, University of Mazandaran, Babolsar, 47416-95447, Iran.
J Mol Graph Model. 2020 Dec;101:107731. doi: 10.1016/j.jmgm.2020.107731. Epub 2020 Sep 2.
The upgrading of natural gas on the pristine and functionalized NUM-3a -X (X = -Cl, -NH, -F) were studied using Monte Carlo simulations in the grand canonical ensemble (GCMC). The equilibrium structures of the functionalized NUM-3a-X were found and confirmed by the quantum mechanical DFT methods. At first, the adsorptions of the components of the natural gas, CH, CO, HS and N as pure gases in the pristine MOF were calculated, utilizing the common force fields for the MOFs and compared with the available experimental data to find out the best performing ones for the simulation of adsorption of the studied gases. Based on the obtained results, NUM-3a -Cl showed the highest uptake for the pure gases. Also, we found that the adsorption of CO on NUM-3a -X (X = -Cl, -NH, -F) is higher than that of other gases. Furthermore, our GCMC simulations revealed that the inclusion of functional groups increases the CO selectivity in binary mixtures. In addition, the selectivity of NUM-3a-Cl for CO was found to be higher than that the other studied MOFs. The simulated CO selectivity were in the order of CO/N > CO/CH. Our results indicated that the inclusion of electron withdrawing functional groups can enhance the performance of a MOF for CO separation applications. In addition, the isosteric heats of adsorption and Henry's law coefficients were studied.
在巨正则系综（GCMC）中使用蒙特卡罗模拟研究了原始的和功能化的NUM - 3a - X（X = -Cl、-NH、-F）上天然气的升级情况。通过量子力学密度泛函理论（DFT）方法找到了并确认了功能化NUM - 3a - X的平衡结构。首先，利用适用于金属有机框架（MOF）的常用力场计算了天然气成分CH₄、CO₂、H₂S和N₂作为纯气体在原始MOF中的吸附情况，并与现有的实验数据进行比较，以找出模拟所研究气体吸附效果最佳的力场。基于所得结果，NUM - 3a - Cl对纯气体的吸附量最高。此外，我们发现CO在NUM - 3a - X（X = -Cl、-NH、-F）上的吸附高于其他气体。而且，我们的GCMC模拟表明，引入官能团会提高二元混合物中CO的选择性。另外，发现NUM - 3a - Cl对CO的选择性高于其他所研究的MOF。模拟的CO选择性顺序为CO/N₂ > CO/CH₄。我们的结果表明，引入吸电子官能团可以提高MOF在CO分离应用中的性能。此外，还研究了等量吸附热和亨利定律系数。
