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La unión altamente selectiva y reversible de O2 en Cr3 (en 1,3,5-benzenetricarboxilato) 2 es altamente selectiva y
Leslie J Murray1, Mircea Dinca, Junko Yano
1Department of Chemistry, University of California, Berkeley, California 94720, USA.
Journal of the American Chemical Society
|May 21, 2010
Resumen
Este estudio introduce un nuevo marco metálico-orgánico basado en cromo, Cr(3)(BTC)(2), para la adsorción selectiva de oxígeno. Este material exhibe una excepcional selectividad O(2)/N(2), crucial para las aplicaciones de separación de gases.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Química Inorgánica La Química Inorgánica es la química inorgánica.
- Nanotecnología La nanotecnología es la nanotecnología.
Sus antecedentes:
- Las estructuras metálicas orgánicas (MOF) son materiales porosos con propiedades sintonizables.
- La adsorción selectiva de gases es crítica para aplicaciones como la separación y el almacenamiento de gases.
- Los MOF basados en cromo ofrecen características electrónicas y estructurales únicas.
Objetivo del estudio:
- Para sintetizar y caracterizar un nuevo marco metálico-orgánico basado en cromo, Cr(3)(BTC)(2).
- Para investigar las propiedades de adsorción de gas de Cr{3){BTC}{2), en particular para el oxígeno y el nitrógeno.
- Para explorar el potencial de Cr(3)(BTC)(2) para la captura selectiva de oxígeno.
Principales métodos:
- Síntesis de Cr{3}{BTC}{2} a través de la reacción de Cr{CO}{6} con el ácido trimesico en DMF.
- Desolución del marco mediante el intercambio de DMF por metanol y calentamiento bajo vacío.
- Las mediciones de adsorción de gas (N(2) a 77 K, O(2) y N(2) a 298 K).
- Análisis espectroscópico (infrarrojo, absorción de rayos X) y difracción de polvo de neutrones.
Principales resultados:
- El material sintetizado, Cr3BTC2, es isostructural a Cu3BTC2 y posee una gran superficie (1810 m2BTC2) /g de BET.
- Cr{3}{BTC}{2} exhibe un notable factor de selectividad O{2}/N{2} de 22 a 298 K, con una alta absorción de O{2} (11 por ciento en peso) a baja presión.
- Los datos espectroscópicos y de difracción confirman la unión de O2 a través de la transferencia parcial de carga a los centros de Cr2, alterando las distancias Cr-Cr.
Conclusiones:
- Cr3BTC2 es un material prometedor para la captura y separación selectiva de oxígeno.
- El mecanismo de unión de O2 implica la interacción con los centros de Cr2 expuestos.
- El marco demuestra la adsorción / desorción reversible de O2 durante múltiples ciclos.
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