Thermodynamics and kinetics of gas storage in porous liquids
The recent synthesis of organic molecular liquids with permanent porosity (Giri et al., Nature, 2015, 527, 216) opens up exciting new avenues for gas capture, storage, and separation. Using molecular dynamics simulations, we study the thermodynamics and kinetics for the storage of CH4, CO2, and N2 molecules in porous liquids consisting of crown-ether substituted cage molecules in a 15-crown-5 solvent. It is found that the gas storage capacity per cage molecule follows the order of CH4 > CO2 > N2, which does not correlate simply with the size of gas molecules. Different gas molecules are stored inside the cage differently, e.g., CO2 molecules prefer the cage s core while CH4 molecules favor both the core and the branch regions. All gas molecules considered can enter the cage essentially without energy barriers, and their dynamics inside the cage are only slightly hindered by the nanoscale confinement. In addition, all gas molecules can leave the cage on nanosecond time scale by overcoming a modest energy penalty. The molecular mechanisms of these observations are clarified.
- Authors:
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[1]
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- Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Publication Date:
- Grant/Contract Number:
- AC05-00OR22725
- Type:
- Accepted Manuscript
- Journal Name:
- Journal of Physical Chemistry. B, Condensed Matter, Materials, Surfaces, Interfaces and Biophysical Chemistry
- Additional Journal Information:
- Journal Volume: 120; Journal Issue: 29; Journal ID: ISSN 1520-6106
- Publisher:
- American Chemical Society
- Research Org:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Center for Nanophase Materials Sciences (CNMS)
- Sponsoring Org:
- USDOE Office of Science (SC)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
- OSTI Identifier:
- 1287030