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Identificación de los sitios activos en la oxidación de CO y el desplazamiento de agua-gas sobre los catalizadores Pt
Kunlun Ding1, Ahmet Gulec2, Alexis M Johnson1
1Department of Chemistry, Northwestern University, Evanston, IL 60208, USA.
Science (New York, N.Y.)
|September 5, 2015
Resumen
Los átomos individuales de platino no son sitios catalíticos activos para la oxidación de CO o el desplazamiento de agua-gas. La espectroscopia infrarroja puede distinguir átomos de platino individuales de las nanopartículas, revelando que las nanopartículas de platino son los sitios activos.
Área de la Ciencia:
- Catálisis
- Ciencias de los materiales
- Espectroscopia
Sus antecedentes:
- Comprender los sitios activos catalíticos es crucial para el diseño de catalizadores heterogéneos eficientes.
- Estudios recientes sugieren que los átomos individuales de platino (Pt) pueden ser sitios catalíticos muy activos.
Objetivo del estudio:
- Para distinguir y cuantificar directamente los átomos individuales de platino de las nanopartículas utilizando la espectroscopia infrarroja.
- Investigar la actividad catalítica de los átomos individuales de platino frente a las nanopartículas en las reacciones de oxidación de CO y desplazamiento de agua-gas.
Principales métodos:
- Utilizando la espectroscopia infrarroja para la caracterización y cuantificación directa de las especies de platino.
- Realización de reacciones catalíticas a baja temperatura (oxidación de CO, desplazamiento agua-gas) para evaluar la actividad.
Principales resultados:
- La espectroscopia infrarroja diferencia efectivamente los átomos individuales de platino de las nanopartículas.
- Solo las nanopartículas de platino mostraron actividad catalítica para la oxidación de CO y el desplazamiento de agua-gas a bajas temperaturas.
- Los átomos individuales de platino no mostraron actividad, posiblemente debido a la fuerte unión de CO.
Conclusiones:
- Las nanopartículas de platino, no los átomos individuales, son los sitios activos para la oxidación de CO a baja temperatura y el desplazamiento de agua a gas.
- La espectroscopia infrarroja es una herramienta valiosa para caracterizar átomos y nanopartículas de platino.
- El fuerte enlace de CO limita el potencial catalítico de los átomos individuales de platino.
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