官能团修饰对MOF-5的气体分子吸附影响

Influence of Functional Group Decoration on Gas Adsorption in MOF-5

采用紧束缚近似计算方法,研究了金属有机骨架(MOF-5)和不同官能团(―NO2,―NH2,―CH3,―OZn)修饰后的MOF-5不同吸附位点的CO2等温室气体和部分工业废气吸附性能以及对不同气体的选择性吸附能力.结果表明,对于未修饰的MOF-5,位点I和II是主要的吸附位点,最大吸附能可达-0.25eV.官能团修饰提高了MOF-5对CO2的吸附能力,其与官能团活性和局部位型密切相关.其中―NO2修饰使各位点的CO2吸附能力都有一定提高.同时,―NO2修饰后MOF-5对空气环境(O2,N2,H2O,CO2),工业废气环境(CO2,CO,NO,NO2,SO2,SO3)中不同气体有明显的选择性吸附能力.

This paper presents a comprehensive study about the adsorption ability of five different sites in metal-organic framework （MOF-5）,including pure and different groups （―NO2,―NH2,―CH3,―OZn） decorated ones,for CO2 and other greenhouse gases and industrial waste gases.The selective adsorption ability was investigated based on the tight binding approximation method.The results show that sites I and II are the major adsorption sites for pure MOF-5.The highest adsorption energy can be-0.25 eV.Group decoration enhances the adsorption ability of MOF-5 when adsorbing CO2,which is highly related to the activity of decorated groups and the local configurations.Among these groups,―NO2 enhances the adsorption ability of all sites for CO2 absorption.The ―NO2 decorated MOF-5 shows an obvious selective adsorption ability for different gases in the air environment （O2,N2,H2O,CO2） and for industrial waste gases environment （CO2,CO,NO,NO2,SO2,SO3）.