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

Abstract

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).