CO 2 adsorption in mono-, di- and trivalent cation-exchanged metal-organic frameworks: A molecular simulation study

Handle URI:
http://hdl.handle.net/10754/562100
Title:
CO 2 adsorption in mono-, di- and trivalent cation-exchanged metal-organic frameworks: A molecular simulation study
Authors:
Chen, Yifei; Nalaparaju, Anjaiah; Eddaoudi, Mohamed ( 0000-0003-1916-9837 ) ; JIANG, Jianwen
Abstract:
A molecular simulation study is reported for CO 2 adsorption in rho zeolite-like metal-organic framework (rho-ZMOF) exchanged with a series of cations (Na +, K +, Rb +, Cs +, Mg 2+, Ca 2+, and Al 3+). The isosteric heat and Henry's constant at infinite dilution increase monotonically with increasing charge-to-diameter ratio of cation (Cs + < Rb + < K + < Na + < Ca 2+ < Mg 2+ < Al 3+). At low pressures, cations act as preferential adsorption sites for CO 2 and the capacity follows the charge-to-diameter ratio. However, the free volume of framework becomes predominant with increasing pressure and Mg-rho-ZMOF appears to possess the highest saturation capacity. The equilibrium locations of cations are observed to shift slightly upon CO 2 adsorption. Furthermore, the adsorption selectivity of CO 2/H 2 mixture increases as Cs + < Rb + < K + < Na + < Ca 2+ < Mg 2+ ≈ Al 3+. At ambient conditions, the selectivity is in the range of 800-3000 and significantly higher than in other nanoporous materials. In the presence of 0.1% H 2O, the selectivity decreases drastically because of the competitive adsorption between H 2O and CO 2, and shows a similar value in all of the cation-exchanged rho-ZMOFs. This simulation study provides microscopic insight into the important role of cations in governing gas adsorption and separation, and suggests that the performance of ionic rho-ZMOF can be tailored by cations. © 2012 American Chemical Society.
KAUST Department:
Biological and Environmental Sciences and Engineering (BESE) Division; Physical Sciences and Engineering (PSE) Division; Chemical Science Program; Advanced Membranes and Porous Materials Research Center; Functional Materials Design, Discovery and Development (FMD3)
Publisher:
American Chemical Society
Journal:
Langmuir
Issue Date:
28-Feb-2012
DOI:
10.1021/la205152f
Type:
Article
ISSN:
07437463
Sponsors:
This work is supported by the National Research Foundation of Singapore (R-279-000-261-281) and the National University of Singapore (R-279-000-297-112).
Appears in Collections:
Articles; Advanced Membranes and Porous Materials Research Center; Physical Sciences and Engineering (PSE) Division; Functional Materials Design, Discovery and Development (FMD3); Chemical Science Program; Biological and Environmental Sciences and Engineering (BESE) Division

Full metadata record

DC FieldValue Language
dc.contributor.authorChen, Yifeien
dc.contributor.authorNalaparaju, Anjaiahen
dc.contributor.authorEddaoudi, Mohameden
dc.contributor.authorJIANG, Jianwenen
dc.date.accessioned2015-08-03T09:44:46Zen
dc.date.available2015-08-03T09:44:46Zen
dc.date.issued2012-02-28en
dc.identifier.issn07437463en
dc.identifier.doi10.1021/la205152fen
dc.identifier.urihttp://hdl.handle.net/10754/562100en
dc.description.abstractA molecular simulation study is reported for CO 2 adsorption in rho zeolite-like metal-organic framework (rho-ZMOF) exchanged with a series of cations (Na +, K +, Rb +, Cs +, Mg 2+, Ca 2+, and Al 3+). The isosteric heat and Henry's constant at infinite dilution increase monotonically with increasing charge-to-diameter ratio of cation (Cs + < Rb + < K + < Na + < Ca 2+ < Mg 2+ < Al 3+). At low pressures, cations act as preferential adsorption sites for CO 2 and the capacity follows the charge-to-diameter ratio. However, the free volume of framework becomes predominant with increasing pressure and Mg-rho-ZMOF appears to possess the highest saturation capacity. The equilibrium locations of cations are observed to shift slightly upon CO 2 adsorption. Furthermore, the adsorption selectivity of CO 2/H 2 mixture increases as Cs + < Rb + < K + < Na + < Ca 2+ < Mg 2+ ≈ Al 3+. At ambient conditions, the selectivity is in the range of 800-3000 and significantly higher than in other nanoporous materials. In the presence of 0.1% H 2O, the selectivity decreases drastically because of the competitive adsorption between H 2O and CO 2, and shows a similar value in all of the cation-exchanged rho-ZMOFs. This simulation study provides microscopic insight into the important role of cations in governing gas adsorption and separation, and suggests that the performance of ionic rho-ZMOF can be tailored by cations. © 2012 American Chemical Society.en
dc.description.sponsorshipThis work is supported by the National Research Foundation of Singapore (R-279-000-261-281) and the National University of Singapore (R-279-000-297-112).en
dc.publisherAmerican Chemical Societyen
dc.titleCO 2 adsorption in mono-, di- and trivalent cation-exchanged metal-organic frameworks: A molecular simulation studyen
dc.typeArticleen
dc.contributor.departmentBiological and Environmental Sciences and Engineering (BESE) Divisionen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentChemical Science Programen
dc.contributor.departmentAdvanced Membranes and Porous Materials Research Centeren
dc.contributor.departmentFunctional Materials Design, Discovery and Development (FMD3)en
dc.identifier.journalLangmuiren
dc.contributor.institutionDepartment of Chemical and Biomolecular Engineering, National University of Singapore, 117576, Singapore, Singaporeen
kaust.authorEddaoudi, Mohameden
kaust.authorChen, Yifeien
kaust.authorNalaparaju, Anjaiahen
kaust.authorJIANG, Jianwenen
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