Abstract: The density functional theory is used to study the adsorption mechanism of volatile organic compounds(VOCs)on MOF-5,including methanol,acetaldehyde and acetone.The results show that these VOC molecules are adsorbed in four adsorption sites of MOF-5 and Zn₄O clusters are the most favorable adsorption sites.Comparison and analysis on the structural properties and adsorption energy of VOC molecules adsorbed on MOF-5 indicate that the functional groups play the key role.The introduction of electron-withdrawing functional groups to the aromatic rings of MOF-5 increases the interaction between organic molecules containing hydroxyl(such as methanol)and MOF-5 frameworks.The introduction of electron-donating functional groups and oxygen containing groups to the organic linkers increases the adsorption capacity of organic molecules containing carbonyl(such as acetaldehyde and acetone)in MOF-5.

Key words: metal-organic framework, density functional theory, methanol, acetaldehyde, acetone, adsorption, volatile organic compounds

摘要： 采用密度泛函理论对甲醇、乙醛和丙酮3种VOCs气体在MOF-5中的吸附机理进行了系统的理论研究,结果表明:3种气体分子在MOF-5中的吸附位置主要有4种,分别为大胞腔中的金属簇Zn₄O、苯环BDC位置和小胞腔中的金属簇Zn₄O、苯环BDC位置,其中在金属簇Zn₄O位置吸附能皆为最大。对比甲醇、乙醛和丙酮的结构特性和在MOF-5中的吸附能,结果预测:在有机配体苯环中引入吸电子基团有利于甲醇这类含有羟基基团的有机分子在MOF-5上的吸附,而引入给电子基团或更多含氧官能团,则有利于增强乙醛和丙酮这类含有羰基基团的有机分子与MOF-5的吸附作用。

关键词: 金属-有机骨架材料, 密度泛函理论, 甲醇, 乙醛, 丙酮, 吸附, VOCs