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Actividad de evolución del oxígeno independiente de las facetas del β-NiOOH puro: diferentes químicas que conducen a
Ananth Govind Rajan1, John Mark P Martirez2, Emily A Carter1,2,3
1Department of Mechanical and Aerospace Engineering , Princeton University , Princeton , New Jersey 08544-5263 , United States.
Journal of the American Chemical Society
|January 22, 2020
Resumen
El oxihidróxido de β-níquel (β-NiOOH) es un electrocatalizador clave para la reacción de evolución del oxígeno (OER) en la división del agua. Este estudio revela que las diferentes facetas cristalinas del β-NiOOH exhiben diferentes actividades OER, con facetas de bajo índice que contribuyen al rendimiento general.
Área de la Ciencia:
- Ciencias de los materiales
- La electroquímica
- Química computacional
Sus antecedentes:
- La reacción de evolución del oxígeno (OER) es crucial para la división del agua, pero sigue siendo un desafío.
- El oxihidróxido de β-níquel (β-NiOOH) es un electrocatalizador prometedor para el OER.
- Comprender el papel de las diferentes facetas cristalográficas es clave para optimizar el rendimiento del β-NiOOH.
Objetivo del estudio:
- Investigar las actividades OER de las facetas (0001) y (1010) del β-NiOOH puro.
- Para modelar y comparar sitios activos en estas facetas utilizando métodos computacionales avanzados.
- Aclarar los mecanismos subyacentes a la REA en las diferentes facetas de la β-NiOOH.
Principales métodos:
- Se emplearon cálculos de la teoría funcional de la densidad híbrida (DFT).
- Modelado de varios sitios activos en las facetas (0001) y (1010) de β-NiOOH.
- Evaluación de los sobrepotenciales OER termodinámicos para las diferentes vías de reacción.
Principales resultados:
- Se observaron distintas actividades OER para diferentes sitios activos en las facetas (0001) y (1010).
- Los potenciales excesivos OER más bajos calculados para estas facetas fueron comparables a los sitios estudiados anteriormente.
- Los sitios activos en las facetas investigadas operan a través de diferentes mecanismos de REA.
Conclusiones:
- Todas las facetas de bajo índice de β-NiOOH investigadas pueden contribuir a la actividad OER observada experimentalmente.
- Las vías de sobrepotencial OER más bajas dependen de sitios activos específicos, intermedios y estabilización de facetas.
- La consideración integral de los sitios activos y los mecanismos de reacción es fundamental para el diseño de electrocatalizadores β-NiOOH eficientes.
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