Highly selective carbon dioxide sorption in an organic molecular porous material.
The organic molecular porous material 1 obtained by recrystallization of cucurbit[6]uril (CB[6]) from HCl shows a high CO(2) sorption capacity at 298 K, 1 bar. Most interestingly, 1 showed the highest selectivity of CO(2) over CO among the known porous materials so far. The remarkable selectivity of CO(2) may be attributed to the exceptionally high enthalpy of adsorption (33.0 kJ/mol). X-ray crystal structure analysis of CO(2) adsorbed 1 revealed three independent CO(2) sorption sites: two in the 1D channels (A and B) and one in the molecular cavities (C). The CO(2) molecules adsorbed at sorption site A near the wall of the 1D channels interact with 1 through hydrogen bonding and at the same time interact with those at site B mainly through quadrupole-quadrupole interaction in a T-shaped arrangement. Interestingly, two CO(2) molecules are included in the CB[6] cavity (site C), interacting not only with the carbonyl groups of CB[6] but also with each other in a slipped-parallel geometry. The exceptionally selective CO(2) sorption properties of 1 may find useful applications in the pressure swing adsorption (PSA) process for CO(2) separation not only in the steel industry but also in other industries such as natural gas mining.
Kim
Hyunuk
H
National Creative Research Initiative Center for Smart Supramolecules, Department of Chemistry, and Division of Advanced Materials Science, Pohang University of Science and Technology, San 31 Hyojadong, Pohang 790-784, Republic of Korea.
Kim
Yonghwi
Y
Yoon
Minyoung
M
Lim
Soyoung
S
Park
Se Min
SM
Seo
Gon
G
Kim
Kimoon
K
D000327:Adsorption; D001896:Boron Compounds / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D016062:Porosity
D001896:Boron Compounds; D002245:Carbon Dioxide