Kinetic isotope effect for H2 and D2 quantum molecular sieving in adsorption/desorption on porous carbon materials

Adsorption and desorption of H(2) and D(2) from porous carbon materials, such as activated carbon at 77 K, are usually fully reversible with very rapid adsorption/desorption kinetics. The adsorption and desorption of H(2) and D(2) at 77 K on a carbon molecular sieve (Takeda 3A), where the kinetic se...

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Detalles Bibliográficos
Autores: Zhao, Xuebo, Villar Rodil, Silvia, Fletcher, Ashleigh J, Thomas, K Mark
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2006
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/415170
Acceso en línea:http://hdl.handle.net/10261/415170
https://api.elsevier.com/content/abstract/scopus_id/33745686202
Access Level:acceso abierto
Palabra clave:http://metadata.un.org/sdg/7
http://metadata.un.org/sdg/9
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Descripción
Sumario:Adsorption and desorption of H(2) and D(2) from porous carbon materials, such as activated carbon at 77 K, are usually fully reversible with very rapid adsorption/desorption kinetics. The adsorption and desorption of H(2) and D(2) at 77 K on a carbon molecular sieve (Takeda 3A), where the kinetic selectivity was incorporated by carbon deposition, and a carbon, where the pore structure was modified by thermal annealing to give similar pore structure characteristics to the carbon molecular sieve substrate, were studied. The D(2) adsorption and desorption kinetics were significantly faster (up to x1.9) than the corresponding H(2) kinetics for specific pressure increments/decrements. This represents the first experimental observation of kinetic isotope quantum molecular sieving in porous materials due to the larger zero-point energy for the lighter H(2), resulting in slower adsorption/desorption kinetics compared with the heavier D(2). The results are discussed in terms of the adsorption mechanism.