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Desproporción inducida por protones de iones de metales de transición activos de Jahn-Teller en óxidos debido a la
Hooman Yaghoobnejad Asl1, Arumugam Manthiram1
1Materials Science and Engineering Program and Texas Materials Institute, University of Texas at Austin, Austin, Texas 78712, United States.
Journal of the American Chemical Society
|December 7, 2020
Resumen
Los óxidos de metales de transición activos de Jahn-Teller sufren cambios de fase y disolución iónica debido a la inestabilidad electrónica. La exposición a protones desencadena una reacción acoplada ácido-base/redox, causando una desproporción en estos materiales críticos.
Área de la Ciencia:
- Ciencias de los materiales
- Química
- Física del estado sólido
Sus antecedentes:
- Los óxidos de metales de transición activos de Jahn-Teller exhiben una reactividad química interfacial compleja.
- Las transformaciones de fase no controladas y la disolución de iones de metales de transición degradan el rendimiento en aplicaciones como las baterías de iones de litio.
Objetivo del estudio:
- Para aclarar la inestabilidad de la estructura electrónica fundamental que conduce a las distorsiones de Jahn-Teller.
- Para explicar el mecanismo detrás de la desproporción inducida por protones, la transformación de fase y la disolución de iones metálicos.
Principales métodos:
- Se realizaron análisis electrónicos de la estructura.
- Se llevaron a cabo 18 experimentos de etiquetado de isótopos.
Principales resultados:
- La inestabilidad de la estructura electrónica que conduce a la distorsión de Jahn-Teller se identifica como la fuerza motriz.
- Se presenta un mecanismo que involucra reacciones ácido-base/redox acopladas para la desproporción inducida por protones.
Conclusiones:
- La exposición a protones desencadena una desproporción y disolución espontáneas en óxidos de metales de transición activos de Jahn-Teller.
- La comprensión de este mecanismo es crucial para estabilizar las tecnologías basadas en óxidos y prevenir la degradación del rendimiento.
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