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Ajuste de la conducción intrínseca y extrínseca de protones en estructuras orgánicas metálicas por la contracción de
Norman E Wong1, Padmini Ramaswamy1, Andrew S Lee1
1Department of Chemistry, University of Calgary , 2500 University Drive NW, Calgary, Alberta T2N 1N4, Canada.
Journal of the American Chemical Society
|September 28, 2017
Resumen
Las estructuras metal-orgánicas de lantánidos muestran una conductividad de protones ajustable. Los tamaños de partículas más grandes en los complejos La y Pr se correlacionan con una mayor conductividad, desafiando las teorías de conducción mediada por el límite de grano.
Área de la Ciencia:
- Ciencias de los materiales
- Química del estado sólido
- Nanotecnología
Sus antecedentes:
- La conductividad de protones en estructuras metal-orgánicas (MOF) es crucial para las aplicaciones energéticas.
- La contracción del lantánido ofrece una ruta para ajustar sistemáticamente las propiedades del MOF.
Objetivo del estudio:
- Sintetice y caracterice las MOFs lantánidas isomórficas.
- Investigar el efecto de la contracción del lantánido en la conductividad de los protones.
- Correlación de las características estructurales con los mecanismos de transporte de protones.
Principales métodos:
- Síntesis y caracterización de siete MOFs lantánidos isomorfos (familia PCMOF-5).
- Aplicación LeBail para analizar las dimensiones de las células unitarias y las vías de canalización.
- Las mediciones de conductividad de protones.
- Difracción de rayos X de cristal único y microscopía electrónica de barrido.
Principales resultados:
- La familia PCMOF-5 exhibe canales 1-D llenos de agua que facilitan la transferencia de protones.
- La contracción de lantánidos varió sistemáticamente las dimensiones de las células unitarias y las vías de transferencia de protones.
- La conductividad de los protones fue más alta para los complejos La y Pr (10^-3 S cm^-1).
- Se observaron tamaños de partículas más grandes en complejos de La y Pr de alta conducción, lo que contradice las teorías de conducción del límite de grano.
Conclusiones:
- El ajuste sistemático de la conductividad de protones se puede lograr a través de la contracción de lantánidos en MOF.
- Las vías intrínsecas, no los límites de grano, probablemente dominan la conducción de protones en esta serie.
- Los hallazgos proporcionan información sobre el diseño de MOF conductores de protones eficientes para aplicaciones energéticas.
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