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金属有机骨架是一种新型的温室气体CO_2吸附材料。本文采用密度泛函理论(DFT)方法研究CO_2在MOF-5有机链上的6种不同吸附位置及其3种不同构型下的吸附行为。考虑GGA水平下三种不同泛函对计算结果的影响,对比发现GGA/PW91泛函能够较好地计算CO_2分子与有机链原子之间的弱范德华力;发现CO_2分子与苯环边相交以及与苯环上的碳原子平行是两种吸附能最大的构型;利用Br原子替代苯环上的H原子可以显著增强对CO_2分子的吸附能力,为设计具有较高CO_2吸附能力的MOFs材料提供理论依据。
Metal-organic framework is a new type of CO 2 adsorbent for greenhouse gases. In this paper, the density functional theory (DFT) method was used to study the adsorption behavior of CO_2 at six different adsorption sites on MOF-5 organic chains and in three different configurations. Considering the effect of three different functionalities on the calculated results at GGA level, it is found that the GGA / PW91 functional can be used to calculate the weak van der Waals forces between the CO 2 molecules and the organic chain atoms. The parallel arrangement of the carbon atoms on the benzene ring is the two configurations with the largest adsorption energy. The Br atom can replace the H atom on the benzene ring to enhance the adsorption capacity of CO 2 molecules, providing the theory for the design of MOFs with higher CO 2 adsorption capacity in accordance with.