title: An In-Depth Structural Study of the Carbon Dioxide Adsorption Process in the Porous Metal-Organic Frameworks CPO-27-M.
abstract: The CO2adsorption process in the family of porous metal-organic framework materials CPO-27-M (M=Mg, Mn, Co, Ni, Cu, and Zn) was studied by variable-temperature powder synchrotron X-ray diffraction under isobaric conditions. The Rietveld analysis of the data provided a time-lapse view of the adsorption process on CPO-27-M. The results confirm the temperature-dependent order of occupation of the three adsorption sites in the pores of the CPO-27-M materials. In CPO-27-M (M=Mg, Mn, Co, Ni, and Zn), the adsorption sites are occupied in sequential order, primarily because of the high affinity of CO2for the open metal sites. CPO-27-Cu deviates from this stepwise mechanism, and the adsorption sites at the metal cation and the second site are occupied in parallel. The temperature dependence of the site occupancy of the individual CO2adsorption sites derived from the diffraction data is reflected in the shape of the volumetric sorption isotherms. The fast kinetics and high reversibility observed in these experiments support the suitability of these materials for use in temperature- or pressure-swing processes for carbon capture.
authors.affiliation: Department of Chemistry, University of Bergen, P.O. Box 7803, N-5020, Bergen, Norway.
authors.forename: Breogán
authors.identifier: 0000-0003-2302-8623
authors.initials: B
authors.lastname: Pato-Doldán
authors.affiliation: Department of Chemistry, University of Bergen, P.O. Box 7803, N-5020, Bergen, Norway.
authors.forename: Mali H
authors.identifier: 0000-0003-3274-9967
authors.initials: MH
authors.lastname: Rosnes
authors.affiliation: Department of Chemistry, University of Bergen, P.O. Box 7803, N-5020, Bergen, Norway.
authors.forename: Pascal D C
authors.identifier: 0000-0001-5731-2118
authors.initials: PDC
authors.lastname: Dietzel
mesh_terms: D000327:Adsorption; D002245:Carbon Dioxide / Q000737:chemistry*; D018360:Crystallography, X-Ray; D008670:Metals / Q000737:chemistry*; D015394:Molecular Structure; D009930:Organic Chemicals / Q000737:chemistry*; D016062:Porosity; D013696:Temperature
chemical_list: D008670:Metals; D009930:Organic Chemicals; D002245:Carbon Dioxide
keywords: adsorption; carbon storage; metal-organic frameworks; microporous materials; structure elucidation