Molecular simulation of CO2 adsorption in the presence of water in single-walled carbon nanotubes

Liu, Lang and Bhatia, Suresh K. (2013) Molecular simulation of CO2 adsorption in the presence of water in single-walled carbon nanotubes. Journal of Physical Chemistry C: Nanomaterials, Interfaces and Hard Matter, 117 26: 13479-13491. doi:10.1021/jp403477y


Author Liu, Lang
Bhatia, Suresh K.
Title Molecular simulation of CO2 adsorption in the presence of water in single-walled carbon nanotubes
Formatted title
Molecular simulation of CO2 adsorption in the presence of water in single-walled carbon nanotubes
Journal name Journal of Physical Chemistry C: Nanomaterials, Interfaces and Hard Matter   Check publisher's open access policy
ISSN 1932-7447
1932-7455
Publication date 2013-07-03
Sub-type Article (original research)
DOI 10.1021/jp403477y
Volume 117
Issue 26
Start page 13479
End page 13491
Total pages 13
Place of publication United States
Publisher American Chemical Society
Collection year 2014
Language eng
Formatted abstract
The adsorption of carbon dioxide in the presence of water in single-walled carbon nanotubes is studied using Monte Carlo simulation, at 300, 325, and 350 K. We also investigate the influence of the diameter and chirality of the nanotubes on the adsorption isotherms of CO2. It is observed that increasing the nanotube diameter from 1.36 nm (10, 10) to 2.03 nm (15, 15) leads to enhanced CO2 capacity, while change in chirality has little effect on the adsorption capacity of carbon nanotubes. Our results show that the influence of preadsorbed water on CO2 adsorption is dependent on both the effects of excluded volume and H2O–CO2 interactions. The maximum adsorbed amount of CO2 decreases linearly with the loading of water, and drops more rapidly in narrower nanotubes. The structure of water in hydrophobic nanopores is in the form of hydrogen-bonded clusters, and its adsorption does not affect the arrangement and orientation of CO2 molecules (i.e., it does not affect the mechanism of CO2 adsorption). The average size of water clusters coexisting with CO2 depends strongly on the adsorbed amount of CO2; however, it is shown that splitting large water clusters into smaller ones can lead to significant enhancement of CO2 adsorption, due to the resulting stronger water–CO2 interaction. The maximum percentage increase in the excess adsorption of CO2 is as high as 53.4% when a single cluster is split into multiple smaller clusters. This finding demonstrates that the efficiency of CO2 capture from flue gas can be significantly improved by controlling the structure of coexisting water in carbon nanotubes.
Keyword Metal-organic frameworks
High-pressure adsorption
Dynamics simulation
Room-temperature
Activated carbon
High-capacity
Flue-gas
Dioxide
Capture
Membranes
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Chemical Engineering Publications
Official 2014 Collection
 
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Citation counts: TR Web of Science Citation Count  Cited 19 times in Thomson Reuters Web of Science Article | Citations
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