(345e) Identifying Best Core MOFs with Open Mg Sites for CO2/N2 Separation Using Computational Tools
In this study, the CoRE MOF database is screened for MOFs with open Mg sites that are optimal for CO2/N2 separation at flue gas conditions. To this extent, a hierarchical screening approach is employed. First, a geometric approach is used to identify MOFs with open Mg sites. Second, unary adsorption isotherms are determined from a multi-site Langmuir model in which the guest-host interaction energy for the volume element near the open Mg site is computed by periodic density functional theory (DFT) and the remainder of the interactions is calculated by a combination of the TraPPE force field for the sorbate molecules and of the UFF force field for the framework. Third, for MOFs with sufficient CO2 capacity, the binary CO2/N2 adsorption isotherms and selectivities are estimated using the ideal adsorbed solution theory (IAST)2. Fourth, the self diffusivities and transport selectivities are estimated. Finally, first principles simulations are performed for the most promising materials.
1. Chung, Y. G. et al. Computation-Ready, Experimental MetalâOrganic Frameworks: A Tool To Enable High-Throughput Screening of Nanoporous Crystals. Chem. Mater. 26, 6185â6192 (2014).
2. Myers, A. L. & Prausnitz, J. M. Thermodynamics of mixed-gas adsorption. AIChE J. 11, 121â127 (1965).