A520体系气体分子吸附机理的密度泛函理论研究

采用密度泛函理论研究了CO₂、N₂、H₂O、二氯甲烷和三氯甲烷在A520中的吸附位点、吸附构型和吸附能。结果表明，A520中气体的吸附位点主要有两类，对不同的气体有不同的吸附构型。A520对CO₂、N₂、H₂O、二氯甲烷和三氯甲烷气体的最大吸附能分别为-31.69 kJ·mol^-1、-22.33 kJ·mol^-1、-68.59 kJ·mol^-1、-43.35 kJ·mol^-1和-41.62 kJ·mol^-1。从吸附能与A520的结构关系分析得出引入含氧官能团有利于水与MOFs的吸附作用，MOFs孔道大小与客体分子的分子动力学直径相近有利于增强客体分子与MOFs的吸附作用。

Density functional theory study of gas molecule adsorption mechanism in A520 system

The density functional theory was used to study the adsorption sites, conformation and the adsorption energies of carbon dioxide, nitrogen, water, dichloromethane and trichloromethane in A520. The results show that there are mainly two kinds of gas adsorption sites in A520,which have various adsorption conformations for different gases.The largest adsorption energies of A520 for carbon dioxide,nitrogen, water,dichloromethane and trichloromethane are -31.69 kJ·mol-1, -22.33 kJ·mol^-1, -68.59 kJ·mol^-1, -43.35 kJ·mol^-1 and -41.62 kJ·mol^-1 respectively. From the analysis of the relationship between adsorption energy and structure of A520, it is concluded that the adsorption of water can be increased by introducing O containing groups. In addition, the matching of the pore size of MOFs and dynamic diameters of guest molecules can enhance their adsorption in MOFs .