A porous Mg2(dondc) framework (H4dondc = 1,5-dioxido-2,6-naphthalenedicarboxylic acid) with open metal sites was prepared and functionalized with primary or secondary diamines (en = ethylenediamine, mmen = N,N′-dimethylethylenediamine, or ppz = piperazine). The CO2 adsorption was substantial under post-combustion flue gas conditions as compared to other reported metal-organic frameworks. Interestingly, the IR spectroscopic measurements demonstrated that the CO2 adsorption mechanism is based on the combination of physisorption and chemisorption. The CO2 adsorption capacity of 1-mmen was greater than that of 1-en and 1-ppz, which can likely be attributed to the basicity of the free amine groups tethered to the open coordination sites. Ultrahigh selectivity and superior dynamic separation of CO2 over N2 were evident in 1-ppz. Such exceptional CO2 uptake and CO2/N2 selectivity of diamine-functionalized materials hold potential promise for post-combustion CO2 capture applications.
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)