On the Structure-Property Relationships of Cation-Exchanged ZK-5 Zeolites for CO 2 Adsorption
Abstract
The CO2 adsorption properties of cation-exchanged Li-, Na-, K-, and Mg-ZK-5 zeolites were correlated to the molecular structures determined by Rietveld refinements of synchrotron powder X-ray diffraction patterns. Li-, K-, and Na-ZK-5 all exhibited high isosteric heats of adsorption (Qst) at low CO2 coverage, with Na-ZK-5 having the highest Qst (ca. 49 kJ mol-1). Mg2+ was located at the center of the zeolite hexagonal prism with the cation inaccessible to CO2, leading to a much lower Qst (ca. 30 kJ mol-1) and lower overall uptake capacity. Multiple CO2 adsorption sites were identified at a given CO2 loading amount for all four cation-exchanged ZK-5 adsorbents. Site A at the flat eight-membered ring windows and site B/B* in the γ-cages were the primary adsorption sites in Li- and Na-ZK-5 zeolites. Relatively strong dual-cation adsorption sites contributed significantly to an enhanced electrostatic interaction for CO2 in all ZK-5 samples. This interaction gives rise to a migration of Li+ and Mg2+ cations from their original locations at the center of the hexagonal prisms toward the α-cages, in which they interact more strongly with the adsorbed CO2.
- Authors:
-
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark Delaware 19716 USA
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg Maryland 20899 USA
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark Delaware 19716 USA; Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg Maryland 20899 USA
- Publication Date:
- Research Org.:
- Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
- Sponsoring Org.:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- OSTI Identifier:
- 1347013
- Resource Type:
- Journal Article
- Journal Name:
- ChemSusChem
- Additional Journal Information:
- Journal Volume: 10; Journal Issue: 5; Journal ID: ISSN 1864-5631
- Publisher:
- ChemPubSoc Europe
- Country of Publication:
- United States
- Language:
- ENGLISH
- Subject:
- 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
Citation Formats
Pham, Trong D., Hudson, Matthew R., Brown, Craig M., and Lobo, Raul F. On the Structure-Property Relationships of Cation-Exchanged ZK-5 Zeolites for CO 2 Adsorption. United States: N. p., 2017.
Web. doi:10.1002/cssc.201601648.
Pham, Trong D., Hudson, Matthew R., Brown, Craig M., & Lobo, Raul F. On the Structure-Property Relationships of Cation-Exchanged ZK-5 Zeolites for CO 2 Adsorption. United States. https://doi.org/10.1002/cssc.201601648
Pham, Trong D., Hudson, Matthew R., Brown, Craig M., and Lobo, Raul F. 2017.
"On the Structure-Property Relationships of Cation-Exchanged ZK-5 Zeolites for CO 2 Adsorption". United States. https://doi.org/10.1002/cssc.201601648.
@article{osti_1347013,
title = {On the Structure-Property Relationships of Cation-Exchanged ZK-5 Zeolites for CO 2 Adsorption},
author = {Pham, Trong D. and Hudson, Matthew R. and Brown, Craig M. and Lobo, Raul F.},
abstractNote = {The CO2 adsorption properties of cation-exchanged Li-, Na-, K-, and Mg-ZK-5 zeolites were correlated to the molecular structures determined by Rietveld refinements of synchrotron powder X-ray diffraction patterns. Li-, K-, and Na-ZK-5 all exhibited high isosteric heats of adsorption (Qst) at low CO2 coverage, with Na-ZK-5 having the highest Qst (ca. 49 kJ mol-1). Mg2+ was located at the center of the zeolite hexagonal prism with the cation inaccessible to CO2, leading to a much lower Qst (ca. 30 kJ mol-1) and lower overall uptake capacity. Multiple CO2 adsorption sites were identified at a given CO2 loading amount for all four cation-exchanged ZK-5 adsorbents. Site A at the flat eight-membered ring windows and site B/B* in the γ-cages were the primary adsorption sites in Li- and Na-ZK-5 zeolites. Relatively strong dual-cation adsorption sites contributed significantly to an enhanced electrostatic interaction for CO2 in all ZK-5 samples. This interaction gives rise to a migration of Li+ and Mg2+ cations from their original locations at the center of the hexagonal prisms toward the α-cages, in which they interact more strongly with the adsorbed CO2.},
doi = {10.1002/cssc.201601648},
url = {https://www.osti.gov/biblio/1347013},
journal = {ChemSusChem},
issn = {1864-5631},
number = 5,
volume = 10,
place = {United States},
year = {Thu Feb 16 00:00:00 EST 2017},
month = {Thu Feb 16 00:00:00 EST 2017}
}