Unusual Entropy of Adsorbed Methane on Zeolite-Templated Carbon
Abstract
Methane adsorption at high pressures and across a wide range of temperatures was investigated on the surface of three porous carbon adsorbents with complementary structural properties. The measured adsorption equilibria were analyzed using a method that can accurately account for nonideal fluid properties and distinguish between absolute and excess quantities of adsorption, and that also allows the direct calculation of the thermodynamic potentials relevant to adsorption. On zeolite-templated carbon (ZTC), a material that exhibits extremely high surface area with optimal pore size and homogeneous structure, methane adsorption occurs with unusual thermodynamic properties that are greatly beneficial for deliverable gas storage: an enthalpy of adsorption that increases with site occupancy, and an unusually low entropy of the adsorbed phase. The origin of these properties is elucidated by comparison of the experimental results with a statistical mechanical model. The results indicate that temperature-dependent clustering (i.e., reduced configurations) of the adsorbed phase due to enhanced lateral interactions can account for the peculiarities of methane adsorbed on ZTC.
Additional Information
© 2015 American Chemical Society. Received: May 26, 2015; Revised: November 4, 2015; Publication Date (Web): November 4, 2015. This work was supported as part of EFree, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under award number DE-SC0001057. The authors declare no competing financial interest.Attached Files
Supplemental Material - jp5b05021_si_001.pdf
Supplemental Material - jp5b05021_si_002.pdf
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Additional details
- Eprint ID
- 62327
- Resolver ID
- CaltechAUTHORS:20151123-104238733
- DE-SC0001057
- Department of Energy (DOE)
- Created
-
2015-11-23Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field