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Sub-3 nm Pt@Ru hacia un rendimiento sobresaliente de reacción de oxidación de hidrógeno en medios alcalinos
Fei Yang1,2,3, Yian Wang2, Yingdan Cui2
1Eastern Institute for Advanced Study, Eastern Institute of Technology, Ningbo 315200, Zhejiang, China.
Journal of the American Chemical Society
|December 6, 2023
Resumen
Los investigadores desarrollaron nanopartículas de núcleo de Pt@Ru sub-3 nm utilizando un método de impregnación simple. Estos electrocatalizadores avanzados aumentan significativamente la cinética de la reacción de oxidación del hidrógeno para las pilas de combustible de membrana de intercambio de aniones (AEMFC).
Área de la Ciencia:
- Ciencias de los materiales
- La electroquímica
- Nanotecnología
Sus antecedentes:
- Las células de combustible de membrana de intercambio aniónico (AEMFC) son prometedoras para la conversión de hidrógeno, pero enfrentan desafíos debido a la cinética de reacción de oxidación lenta del hidrógeno en medios alcalinos.
- El desarrollo de electrocatalizadores eficientes es crucial para el avance de la tecnología AEMFC.
Objetivo del estudio:
- Para sintetizar nanopartículas de núcleo de Pt@Ru de sub-3 nm altamente activas y estables.
- Para mejorar la cinética de la reacción de oxidación del hidrógeno en los AEMFC.
- Para demostrar un método de síntesis fácil para nanocatalizadores avanzados.
Principales métodos:
- Utilizó un proceso de impregnación simple para reducir secuencialmente el platino (Pt) y el rutenio (Ru) a diferentes temperaturas de recocido, creando nanopartículas de núcleo de Pt@Ru.
- Caracterizó el tamaño, la estructura y la superficie electroquímica de las nanopartículas sintetizadas (ECSA).
- Evaluación del rendimiento del electrocatalizador mediante mediciones del electrodo de disco giratorio (RDE) y ensayos del conjunto de electrodos de membrana (MEA).
Principales resultados:
- Nanopartículas de núcleo de Pt@Ru sintetizadas con un tamaño promedio de ~2.5 nm y una ECSA alta de 166.66 m2 gPt+Ru-1.
- Las densidades de corriente de intercambio alcanzadas (j0) son 8,0 y 5,8 veces más altas que las Pt/C comerciales, siendo la masa normalizada j0 la más alta reportada hasta la fecha.
- Demostró una densidad de potencia máxima de 1,78 W cm-2 en pruebas de MEA, superando el PtRu/C comercial.
Conclusiones:
- El método de impregnación simple es eficaz para sintetizar nanocatalizadores finos de núcleo de Pt@Ru.
- La mayor actividad se atribuye a la transferencia de electrones de Ru a Pt y al tamaño de las partículas ultrafinas.
- Este trabajo destaca el potencial de las nanoestructuras de núcleo para mejorar el rendimiento de AEMFC y la importancia del control de la estructura atómica.
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