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Una clase de catalizadores compuestos de metales no preciosos para pilas de combustible
Rajesh Bashyam1, Piotr Zelenay
1Los Alamos National Laboratory, Materials Physics and Applications, Los Alamos, New Mexico 87545, USA.
Nature
|September 8, 2006
Resumen
Los investigadores desarrollaron catalizadores de nanocompuestos de bajo costo para pilas de combustible de electrolito de polímero (PEFC). Estos catalizadores de metales no preciosos muestran una alta actividad y durabilidad, allanando el camino para vehículos asequibles de cero emisiones.
Área de la Ciencia:
- La electroquímica es electroquímica.
- Ciencia de los materiales Ciencia de los materiales.
- Conversión de energía Conversión de energía.
Sus antecedentes:
- Las pilas de combustible de electrolitos poliméricos (PEFC) son clave para una economía de hidrógeno y vehículos de cero emisiones.
- El alto costo de los catalizadores de platino dificulta la viabilidad comercial de los PEFC.
- Necesidad de alternativas rentables a los catalizadores de platino en los electrodos PEFC.
Objetivo del estudio:
- Para demostrar una nueva clase de catalizadores de nanocompuestos de bajo costo para cátodos PEFC.
- Evaluar la actividad de reducción de oxígeno y la durabilidad de estos nuevos catalizadores.
- Explorar el papel de los polímeros heteroatómicos en la estabilización de metales no preciosos y la creación de sitios activos.
Principales métodos:
- Desarrollo de catalizadores nanocompuestos de (metal no precioso) / (polímero heteroatómico).
- Pruebas de catalizadores compuestos de cobalto y polipirrol en pilas de combustible H2-O2.
- Evaluación del rendimiento, incluyendo pruebas de densidad de potencia y durabilidad durante 100 horas.
Principales resultados:
- El catalizador de cobalto-polipirrol logró densidades de potencia de aproximadamente 0,15 W cm(-2).
- El catalizador no demostró degradación de rendimiento durante más de 100 horas de operación.
- Los polímeros heteroatómicos estabilizaron efectivamente el metal no precioso en el ambiente ácido del cátodo PEFC.
Conclusiones:
- Los nanocompuestos de polímero no metálico/heteroatómico de metales no preciosos representan una alternativa de bajo costo prometedora para los catodos PEFC.
- Estos catalizadores ofrecen una alta actividad de reducción de oxígeno y una buena durabilidad, abordando la barrera de costos del platino.
- Los polímeros heteroatómicos desempeñan un doble papel en la estabilización del catalizador y la generación de sitios activos para mejorar el rendimiento de las pilas de combustible.
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