Microporous metal organic framework [M₂(hfipbb) ₂(ted)] (M=Zn, Co; H₂hfipbb=4,4-(hexafluoroisopropylidene) -bis(benzoic acid); Ted=triethylenediamine): Synthesis, structure analysis, pore characterization, small gas adsorption and CO₂/N₂ separation properties

Carbon dioxide is a greenhouse gas that is a major contributor to global warming. Developing methods that can effectively capture CO₂ is the key to reduce its emission to the atmosphere. Recent research shows that microporous metal organic frameworks (MOFs) are emerging as a promising family of adsorbents that may be promising for use in adsorption based capture and separation of CO₂ from power plant waste gases. In this work we report the synthesis, crystal structure analysis and pore characterization of two microporous MOF structures, [M₂(hfipbb)₂(ted)] (M=Zn (1), Co (2); H₂hfipbb=4,4-(hexafluoroisopropylidene)-bis(benzoic acid); ted=triethylenediamine). The CO₂ and N₂ adsorption experiments and IAST calculations are carried out on [Zn₂(hfipbb) ₂(ted)] under conditions that mimic post-combustion flue gas mixtures emitted from power plants. The results show that the framework interacts with CO₂ strongly, giving rise to relatively high isosteric heats of adsorption (up to 28 kJ/mol), and high adsorption selectivity for CO₂ over N₂, making it promising for capturing and separating CO ₂ from CO₂/N₂ mixtures.