Designed Metal-Organic Frameworks Based on MOF-5 and Their Methane Adsorption Calculation by Grand Canonical Monte <br>Carlo Method

Abstract

10 metal-organic framework molecules (MOFs) were designed based on the idea that the comers of those MOFs are consistent with that of MOF-5 (the complex with 1,4-benzenedicarboxylate as linker and Zn4O cluster as comer) but their linkers were changed into derivatives of 1, 4-benzenedicarboxylate (BDC). Then, methane adsorption of new MOFs was calculated by grand canonical Monte Carlo (GCMC) method at 298 K and 1-10 MPa, and the adsorption amounts were correlated with different substituent groups. The results show that the isosteric heat of adsorption is the most important factor at 298 K and 3.5 MPa, and the adsorption amount is highest when the linker of MOFs is -NO2. At last, a designed MOF, which has 4 nitro groups on the BDC, was constructed and the corresponding methane adsorption amount was also calculated at the same conditions. The calculated amount of excess adsorption reaches 209 cm^3•cm^(-3) and the calculated total adsorption attains 228 cm^3•^(-3) which is 26% higher than the amount of DOE's requirement for methane storage materials.