Adsorption Properties of Amine Grafted MOFs

Metal-organic frameworks (MOFs) show great potential for use in adsorption processes. Post-synthetic modification of MOFs allows for direct customization of pore size and functionality, which is beneficial for selective adsorption. Previous work has shown that MOFs containing coordinatively unsaturated metal sites (CUSs) are capable of facilitating post-synthetic modification. In particular, amines can be introduced into the pore space and will undergo coordination with the metal sites in a process termed amine grafting. (1)

Our research investigates the adsorption properties of MOFs post-synthetically modified by amine grafting. The amines used include ethylenediamine, triethyldiamine, and diethyltriamine. Amine grafting trials are conducted on MOFs such as MIL-101 and Cu-BTC. Adsorption isotherms are experimentally determined for selected gases and compared to the unmodified MOFs. These results along with the implications for gas separations will be discussed.

1) Hwang, Y.K. et. al. Angew. Chem. Int. Ed. 2008, 47, 4144-4148.