Amino-functionalized metal-organic framework for adsorption and separation of dichloromethane and trichloromethane

Zinc-based metal organic framework MOF-5, and its amino-functionalized form IRMOF-3 were successfully synthesized, characterized, and evaluated for the adsorption and separation of dichloromethane (DCM) and trichloromethane (TCM). Adsorption equilibria and kinetics of DCM and TCM on the two samples were measured at 298 K, 308 K, and 318 K. In spite of the reduced porosity of IRMOF-3, the adsorption capacities of DCM and TCM were improved up to 24.5% and 27.4% when compared with MOF-5. Therefore, the additional amino group in the MOF imparts extra adsorption capability on the MOF. The binary adsorption selectivity and diffusion selectivity of DCM and TCM were predicted via the Ideal Adsorbed Solution Theory (IAST) method. The adsorption selectivity and diffusion selectivity of DCM/TCM on the IRMOF-3 were about 5.62 and 3.88 at 298 K and 2.8 kPa, which were higher than those of MOF-5. The improved adsorption capacity and enhanced adsorption selectivity and diffusion selectivity over IRMOF-3 (with amino group) could be attributed to the improved interaction of DCM and TCM with the amino group on the MOF.