Systematic Screening of DMOF-1 with NH2, NO2, Br and Azobenzene Functionalities for Elucidation of Carbon Dioxide and Nitrogen Separation Properties

In this study, dabco MOF-1 (DMOF-1) with four different functional groups (NH₂, NO₂, Br and azobenzene) has been successfully synthesized through systematic control of the synthesis condition of their parent framework. The functionalised DMOF-1 is characterized using various analytical techniques including PXRD, TGA and N₂ sorption. The effect of the various functional groups on the performance of the MOFs for post-combustion CO₂ capture is evaluated. DMOF-1s with polar functional groups are found to have better affinity with CO₂ compared with the parent framework as indicated by higher CO₂ heat of adsorption. However, imparting steric hindrance to the framework as in Azo-DMOF-1 enhances CO₂/N₂ selectivity, potentially as a result of lower N₂ affinity for the framework.