金属-有机骨架材料中甲烷吸附机理的密度泛函理论研究

A Density Functional Theory Study of Methane Adsorption Mechanism in a Metal-Organic Framework

采用密度泛函理论研究了甲烷在MOF-5中的吸附位置、吸附构型和吸附能．结果表明:吸附位置主要有四种, Zn4O簇为最佳吸附位,其吸附能为17.38 kJ·mol-1,高于沸石中的甲烷吸附能．从吸附能与MOF-5的结构关系分析得出:在苯环中引入给电子基团,有利于增强甲烷与MOFs的吸附作用;引入含氧等极性官能团,将增加甲烷吸附位,有利于提高吸附储存量．

The density functional theory was used to study the adsorption sites, conformation and the adsorption energies of methane in MOF-5. The results show that there are four adsorption sites, and the Zn40 clusters are the preferential adsorption sites, for which the adsorption energy is 17.38 kJ.mol^-1, larger than that in zeolites. This work shows that the adsorption energy around the aromatic rings can be increased by introducing electron-donor functional groups. In addition, the introduction of polar functional groups such as O containing groups to the organic linkers can introduce additional adsorption sites that increase methane adsorption capacity.