A combined experimental-computational investigation of carbon dioxide capture in a series of isoreticular zeolitic imidazolate frameworks.
A series of five zeolitic imidazolate frameworks (ZIFs) have been synthesized using zinc(II) acetate and five different 4,5-functionalized imidazole units, namely ZIF-25, -71, -93, -96, and -97. These 3-D porous frameworks have the same underlying topology (RHO) with Brunauer-Emmet-Teller surface areas ranging from 564 to 1110 m(2)/g. The only variation in structure arises from the functional groups that are directed into the pores of these materials, which include -CH(3), -OH, -Cl, -CN, -CHO, and -NH(2); therefore these 3-D frameworks are ideal for the study of the effect of functionality on CO(2) uptake. Experimental results show CO(2) uptake at approximately 800 Torr and 298 K ranging from 0.65 mmol g(-1) in ZIF-71 to 2.18 mmol g(-1) in ZIF-96. Molecular modeling calculations reproduce the pronounced dependence of the equilibrium adsorption on functionalization and suggest that polarizability and symmetry of the functionalization on the imidazolate are key factors leading to high CO(2) uptake.
Morris
William
W
Center for Reticular Chemistry, Department of Chemistry and Biochemistry, University of California-Los Angeles, California 90095, USA.
Leung
Belinda
B
Furukawa
Hiroyasu
H
Yaghi
Omar K
OK
He
Ning
N
Hayashi
Hideki
H
Houndonougbo
Yao
Y
Asta
Mark
M
Laird
Brian B
BB
Yaghi
Omar M
OM