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A Protocol for Safe Lithiation Reactions Using Organolithium Reagents
Published on: November 12, 2016
Regeneración del hidruro de litio y aluminio
Jason Graetz1, James Wegrzyn, James J Reilly
1Energy Sciences and Technology Department, Brookhaven National Laboratory, Upton, New York 11933, USA.
Journal of the American Chemical Society
|December 5, 2008
Resumen
El hidruro de litio y aluminio (LiAlH ((4)) se puede regenerar a partir de sus productos de descomposición utilizando una ruta de baja energía. Este método ofrece una vía prometedora para la recuperación eficiente de material de almacenamiento de hidrógeno.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Ingeniería Química Ingeniería Química.
- Almacenamiento de energía Almacenamiento de energía
Sus antecedentes:
- El hidruro de litio y aluminio (LiAlH4) es un material clave para el almacenamiento de hidrógeno debido a su alta densidad de hidrógeno y baja temperatura de descomposición.
- La regeneración de LiAlH ((4) a partir de sus productos deshidrogenados (LiH y Al) es un desafío debido a la falta de rutas de hidrogenación directa a presiones prácticas.
Objetivo del estudio:
- Desarrollar y demostrar un método de bajo consumo energético para la regeneración de LiAlH ((4) a partir de LiH y Al. catalizado por Ti.
- Para investigar las propiedades termodinámicas del proceso de regeneración.
Principales métodos:
- Hidrogenación de LiH y Al catalizado por Ti en una suspensión de tetrahidrofurano para formar el adducto LiAlH(4).4THF.
- Medición de isotermas de composición de presión para determinar la termodinámica de la reacción.
- Desolución a baja temperatura del adducto para obtener LiAlH cristalino.
Principales resultados:
- Se demostró con éxito una ruta de baja energía para la regeneración de LiAlH ((4).
- La reacción reversible exhibe una pequeña y ligeramente negativa energía libre (ΔG = -1.1 kJ/mol H(2)).
- Se determinó una presión de hidrógeno de equilibrio de poco menos de 1 bar a 300 K para la reacción.
Conclusiones:
- El método desarrollado proporciona una vía eficiente para la regeneración de LiAlH, crucial para su aplicación en el almacenamiento de hidrógeno.
- Los datos termodinámicos sugieren la viabilidad del proceso de regeneración en condiciones suaves.
- La desolución a baja temperatura produce LiAlH ((4) cristalino, adecuado para un uso posterior.
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