Size-matched ligand insertion into Mg-MOF-74 for Hydrocarbon Separationl

Abstract

The metal organic framework (MOF) has advantages of its high porosity and surface area. The Mg-MOF-74 has one-dimensional channel with pore diameter near 1.1nm. Its pore size is too large to separate molecules of molecular scale. To reduce the pore size of Mg-MOF-74, ligands are partitioned into the pore of MOF. 2,4,6-Tri(4-pyridyl)-1,3,5-triazine (tpt) can be partitioned into the pore of Mg-MOF-74, through the interaction between N atom of tpt ligand and open metal site of MOF. Two types of ligand insertion method were approached. The first one is As-synthesized Method (ASM). In this method, tpt ligands are put together at the initial stage of MOF synthesis. The second one is Post-synthesis Method (PSM). In here, the ligands are inserted after the synthesis of MOF. Ligand partitioned Mg-MOF-74 will be characterized through Fourier transform infrared spectroscopy (FTIR), Powder X-ray Diffraction (PXRD) and adsorption isotherm data analysis. In order to test the separation performance for hydrocarbons, diffusivity of C1, C2, C3 and C4 gas will be tested. Also, the selectivity of gas mixtures (between any combination of C1, C2, C3 and C4 gas) will be calculated.