MIGRATION OF HYDROGEN GUEST MOLECULES THROUGH CLATHRATE CAGES.
Electronic structure calculations are performed to determine the barriers to migration of molecular hydrogen in clathrate cages. The barriers are used in a chemical reaction rate expression to determine the rate of H2 migration and the diffusion coefficient for the hydrogen guest molecules. Calcu...
Main Authors: | , |
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Language: | English |
Published: |
2008
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Subjects: | |
Online Access: | http://hdl.handle.net/2429/1098 |
Summary: | Electronic structure calculations are performed to determine the barriers to migration of
molecular hydrogen in clathrate cages. The barriers are used in a chemical reaction rate
expression to determine the rate of H2 migration and the diffusion coefficient for the hydrogen
guest molecules. Calculations are performed for migration of hydrogen guests through pentagonal
and hexagonal clathrate cage faces. Cage faces where the water molecules obey the water rules
and cage faces with Bjerrum L and D defects are considered. The migration barriers were
calculated to be ≈25 kcal/mol from the pentagonal faces and between 5 to 6 kcal/mol for the
hexagonal faces, depending on the orientation of the hydrogen molecule. |
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