Abstract

Metal-organic framework (MOF) is a strong candidate for gas storage and gas separation, which can be modified by various functional groups. In this study, we performed Grand Canonical Monte Carlo (GCMC) and molecular dynamics (MD) simulations to investigate the effect of F, Cl, Br, CHO, NO₂, ethyl (Et), methyl (Me), and SH functional groups on the methane and carbon dioxide adsorption and CH₄/CO₂ separation properties in copper benzene-1,3,5-tricarboxylate (Cu-BTC). Adsorption isotherm of CO₂ and CH₄ indicate that Cu-BTC has a slight adsorption preference for CO₂ over the methane. CH₄ adsorption on the NH₂, Et, and Me derivatives of Cu-BTC is slightly more than the parent Cu-BTC. Furthermore, our results showed that the MOF selectivity changed with the composition, functional group and pressure. Therefore, we will able choose specific condition for special application. MD results reveal that CO₂ molecules more strongly interact with MOF sorption sites than CH₄ molecules and also NH₂–Cu-BTC system has the highest interaction energy. Furthermore, the mean-square displacement (MSD) results show that the motion of the gas molecules is diffusive and they can move more easily within the pores of Cu-BTC and its derivatives.

中文翻译：

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基于Cu-BTC功能化的CH 4和CO 2吸附分离新材料设计：GCMC和MD模拟研究

摘要

金属有机框架（MOF）是气体存储和气体分离的强大候选者，可以通过各种官能团进行修饰。在这项研究中，我们进行了大正则蒙特卡罗（GCMC）和分子动力学（MD）模拟，以研究F，Cl，Br，CHO，NO ₂，乙基（Et），甲基（Me）和SH官能团的影响铜-1,3,5-三羧酸铜（Cu-BTC）中甲烷和二氧化碳的吸附及CH ₄ / CO _2的分离性能 CO ₂和CH _4的吸附等温线表明，Cu-BTC对CO _2的吸附优先于甲烷。CH ₄在NH ₂上的吸附Cu-BTC的，Et和Me衍生物略多于母体Cu-BTC。此外，我们的结果表明，MOF选择性随组成，官能团和压力的变化而变化。因此，我们可以为特殊应用选择特定条件。MD结果表明，与CH ₄分子相比，CO ₂分子与MOF吸附位点的相互作用更强，并且NH ₂ -Cu-BTC系统具有最高的相互作用能。此外，均方位移（MSD）结果表明，气体分子的运动具有扩散性，它们可以在Cu-BTC及其衍生物的孔中更容易移动。