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Hidratos de aluminio complejos de tierras raras: preparación mecanoquímica, estructura cristalina y potencial para el
Claudia Weidenthaler1, André Pommerin, Michael Felderhoff
1Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim, Germany. weidenthaler@mpi-muelheim.mpg.de
Journal of the American Chemical Society
|November 6, 2009
Resumen
Se sintetizaron y caracterizaron nuevos hidratos de aluminio de tierras raras. Estos hidruros complejos muestran potencial como hidruros metálicos de baja temperatura para el almacenamiento reversible de hidrógeno.
Área de la Ciencia:
- Ciencia de los materiales Ciencia de los materiales.
- Química del estado sólido.
- Química Inorgánica La Química Inorgánica es la química inorgánica.
Sus antecedentes:
- Los hidratos de aluminio de tierras raras son materiales complejos con aplicaciones potenciales en el almacenamiento de hidrógeno.
- Comprender su estructura y propiedades térmicas es crucial para el desarrollo de nuevos materiales energéticos.
Objetivo del estudio:
- Para sintetizar y caracterizar nuevos complejos de hidratos de aluminio de tierras raras.
- Para investigar su estructura cristalina, estabilidad térmica y comportamiento de deshidrogenación.
- Evaluar su potencial para el almacenamiento reversible de hidrógeno.
Principales métodos:
- Preparación mecanoquímica de hidratos de aluminio de tierras raras (REAlH(6)).
- Cálculos de la Teoría Funcional de Densidad (DFT) para la determinación de la estructura cristalina.
- Refinamientos preliminares de la estructura utilizando datos experimentales.
- Estudios de termólisis para investigar las vías y productos de deshidrogenación.
- Análisis de las entalpías de descomposición para evaluar la reversibilidad de la hidrogenación.
Principales resultados:
- Se ha sintetizado con éxito un nuevo complejo de hidritos de aluminio de tierras raras (RE = La, Ce, Pr, Nd).
- Se determinó una estructura cristalina trigonal con octaedros aislados [AlH(6) ](3-) puenteados por cationes RE.
- Se observó una disminución en la estabilidad térmica con el aumento del número atómico del elemento de tierras raras.
- Identificó los hidritos de tierras raras (REH(x)) y las aleaciones de aluminio RE como productos de deshidrogenación.
- Las entalpias de descomposición calculadas sugieren potencial para la hidrogenación reversible bajo condiciones moderadas.
Conclusiones:
- Los hidratos de aluminio de tierras raras sintetizados son candidatos prometedores para el almacenamiento de hidrógeno a baja temperatura.
- Su reversibilidad puede ser alcanzable con condiciones de presión y temperatura optimizadas.
- Estos materiales representan una clase interesante de hidritos complejos para aplicaciones energéticas.
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