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Evolución estructural y electroquímica de los sulfuros de níquel durante la reacción de evolución de hidrógeno
Sina Haghverdi Khamene1,2, Noëlle van Dalen1, Mariadriana Creatore1,3
1Department of Applied Physics and Science Education, Eindhoven University of Technology, Eindhoven, the Netherlands.
ChemSusChem
|December 20, 2025
Resumen
Los sulfuros de níquel se transforman en la fase Ni3S2 de alta actividad durante las reacciones de evolución de hidrógeno, mejorando el rendimiento. Esta activación electroquímica, impulsada por la lixiviación de azufre, mejora la estabilidad del catalizador con el tiempo.
Área de la Ciencia:
- Ciencia de los materiales
- Electroquímica
- Catálisis
Sus antecedentes:
- Los sulfuros de níquel son catalizadores electroquímicos rentables para la reacción de evolución de hidrógeno alcalino (HER).
- Existe una comprensión limitada sobre las modificaciones estructurales de los sulfuros de níquel durante la operación prolongada de la HER.
- Investigar estas transformaciones es crucial para desarrollar catalizadores de HER estables y activos.
Objetivo del estudio:
- Investigar la evolución estructural y electroquímica post-electrólisis de varios catalizadores cristalinos de sulfuro de níquel.
- Comprender los mecanismos subyacentes de la transformación y su impacto en el rendimiento de la HER.
- Evaluar la estabilidad a largo plazo de los catalizadores de sulfuro de níquel después de la activación inicial.
Principales métodos:
- Se utilizaron ciclos de voltametría cíclica (CV) y polarización de corriente constante para inducir la HER.
- Se empleó espectroscopia Raman para confirmar las transformaciones de fase estructural.
- Se realizaron análisis de área superficial electroquímica, propiedades de transferencia de carga y cinética.
Principales resultados:
- Todos los sulfuros de níquel se transformaron en Ni3S2, la fase más activa para la HER, después de 500 barridos de CV.
- Esta transformación mejoró el área superficial electroquímica y las propiedades de transferencia de carga.
- Se identificó la lixiviación de azufre como el principal impulsor de la reestructuración y activación, que ocurrió principalmente durante la operación inicial.
Conclusiones:
- Los sulfuros de níquel experimentan un proceso de activación electroquímica durante la HER, convirtiéndose en la fase Ni3S2.
- Esta activación mejora la cinética de la HER al cambiar el paso determinante de la velocidad y mejorar las propiedades del catalizador.
- La lixiviación de azufre es un factor clave en la activación inicial y la estabilización posterior de los catalizadores de sulfuro de níquel para la HER.
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