skip to main content

DOE PAGESDOE PAGES

Title: Anomaly in the Chain Length Dependence of n-Alkane Diffusion in ZIF-4 Metal-Organic Frameworks

Molecular diffusion is commonly found to slow down with increasing molecular size. Deviations from this pattern occur in some host materials with pore sizes approaching the diameters of the guest molecules. A variety of theoretical models have been suggested to explain deviations from this pattern, but robust experimental data are scarcely available. Here in this paper, we present such data, obtained by monitoring the chain length dependence of the uptake of n-alkanes in the zeolitic imidazolate framework ZIF-4. A monotonic decrease in diffusivity from ethane to n-butane was observed, followed by an increase for n-pentane, and another decrease for n-hexane. This observation was confirmed by uptake measurements with n-butane/n-pentane mixtures, which yield faster uptake of n-pentane. Further evidence is provided by the observation of overshooting effects, i.e. by transient n-pentane concentrations exceeding the (eventually attained) equilibrium value. Accompanying grand canonical Monte Carlo simulations reveal, for the larger n-alkanes, significant differences between the adsorbed and gas phase molecular configurations, indicating strong confinement effects within ZIF-4, which, with increasing chain length, may be expected to give rise to configurational shifts facilitating molecular propagation at particular chain lengths.
Authors:
 [1] ;  [2] ;  [3] ;  [3] ;  [1] ;  [3] ; ORCiD logo [2] ;  [1]
  1. Univ. Leipzig, Leipzig (Germany). Faculty of Physics and Earth Sciences
  2. Northwestern Univ., Evanston, IL (United States). Dept. of Chemical and Biological Engineering
  3. Friedrich-Alexander-Univ. Erlangen-Nürnberg, Erlangen (Germany). Erlangen Catalysis Resource Center
Publication Date:
Grant/Contract Number:
SC0008688; HA 1893/17-1; KA 953/35-1; FG02-17ER16362
Type:
Accepted Manuscript
Journal Name:
Molecules
Additional Journal Information:
Journal Volume: 23; Journal Issue: 3; Journal ID: ISSN 1420-3049
Publisher:
MDPI
Research Org:
Univ. of Minnesota, Minneapolis, MN (United States). Nanoporous Materials Genome Center
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Chemical Sciences, Geosciences & Biosciences Division; German Science Foundation (DFG); Alexander von Humboldt Foundation
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; ZIF-4; n-alkanes; transport diffusivity; commensurate/incommensurate adsorption; 32 GCMC simulation
OSTI Identifier:
1474411

Hwang, Seungtaik, Gopalan, Arun, Hovestadt, Maximilian, Piepenbreier, Frank, Chmelik, Christian, Hartmann, Martin, Snurr, Randall, and Kärger, Jörg. Anomaly in the Chain Length Dependence of n-Alkane Diffusion in ZIF-4 Metal-Organic Frameworks. United States: N. p., Web. doi:10.3390/molecules23030668.
Hwang, Seungtaik, Gopalan, Arun, Hovestadt, Maximilian, Piepenbreier, Frank, Chmelik, Christian, Hartmann, Martin, Snurr, Randall, & Kärger, Jörg. Anomaly in the Chain Length Dependence of n-Alkane Diffusion in ZIF-4 Metal-Organic Frameworks. United States. doi:10.3390/molecules23030668.
Hwang, Seungtaik, Gopalan, Arun, Hovestadt, Maximilian, Piepenbreier, Frank, Chmelik, Christian, Hartmann, Martin, Snurr, Randall, and Kärger, Jörg. 2018. "Anomaly in the Chain Length Dependence of n-Alkane Diffusion in ZIF-4 Metal-Organic Frameworks". United States. doi:10.3390/molecules23030668. https://www.osti.gov/servlets/purl/1474411.
@article{osti_1474411,
title = {Anomaly in the Chain Length Dependence of n-Alkane Diffusion in ZIF-4 Metal-Organic Frameworks},
author = {Hwang, Seungtaik and Gopalan, Arun and Hovestadt, Maximilian and Piepenbreier, Frank and Chmelik, Christian and Hartmann, Martin and Snurr, Randall and Kärger, Jörg},
abstractNote = {Molecular diffusion is commonly found to slow down with increasing molecular size. Deviations from this pattern occur in some host materials with pore sizes approaching the diameters of the guest molecules. A variety of theoretical models have been suggested to explain deviations from this pattern, but robust experimental data are scarcely available. Here in this paper, we present such data, obtained by monitoring the chain length dependence of the uptake of n-alkanes in the zeolitic imidazolate framework ZIF-4. A monotonic decrease in diffusivity from ethane to n-butane was observed, followed by an increase for n-pentane, and another decrease for n-hexane. This observation was confirmed by uptake measurements with n-butane/n-pentane mixtures, which yield faster uptake of n-pentane. Further evidence is provided by the observation of overshooting effects, i.e. by transient n-pentane concentrations exceeding the (eventually attained) equilibrium value. Accompanying grand canonical Monte Carlo simulations reveal, for the larger n-alkanes, significant differences between the adsorbed and gas phase molecular configurations, indicating strong confinement effects within ZIF-4, which, with increasing chain length, may be expected to give rise to configurational shifts facilitating molecular propagation at particular chain lengths.},
doi = {10.3390/molecules23030668},
journal = {Molecules},
number = 3,
volume = 23,
place = {United States},
year = {2018},
month = {3}
}

Works referenced in this record:

The first example of commensurate adsorption of atomic gas in a MOF and effective separation of xenon from other noble gases
journal, January 2014
  • Wang, Hao; Yao, Kexin; Zhang, Zhijuan
  • Chemical Science, Vol. 5, Issue 2, p. 620-624
  • DOI: 10.1039/C3SC52348A

DREIDING: a generic force field for molecular simulations
journal, December 1990
  • Mayo, Stephen L.; Olafson, Barry D.; Goddard, William A.
  • The Journal of Physical Chemistry, Vol. 94, Issue 26, p. 8897-8909
  • DOI: 10.1021/j100389a010

Exceptional chemical and thermal stability of zeolitic imidazolate frameworks
journal, June 2006
  • Park, K. S.; Ni, Z.; Cote, A. P.
  • Proceedings of the National Academy of Sciences, Vol. 103, Issue 27, p. 10186-10191
  • DOI: 10.1073/pnas.0602439103