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Mecanismo de descomposición del metanol sobre el catalizador de un solo sitio Pt1/CeO2: un estudio DRIFTS
Zhiyuan Qi, Luning Chen, Shuchen Zhang
1Department of Chemistry, University of California, Berkeley, California 94720, United States.
Journal of the American Chemical Society
|December 28, 2020
Resumen
El platino de un solo sitio en ceria (Pt1 / CeO2) muestra una actividad de descomposición de metanol significativamente mayor. Esta mejora proviene del metanol.
Área de la Ciencia:
- Catálisis heterogénea
- Ciencias de la superficie
- Los nanomateriales
Sus antecedentes:
- Los catalizadores de un solo sitio ofrecen la máxima utilización atómica y un rendimiento único.
- Estudios anteriores mostraron que Pt1/CeO2 es 40 veces más activo que las nanopartículas Pt para la descomposición del metanol.
- Anteriormente faltaba una comprensión a nivel molecular de esta mejora.
Objetivo del estudio:
- Investigar el mecanismo de reacción de la descomposición del metanol en un solo sitio Pt1/CeO2.
- Proponer una vía de reacción a nivel molecular.
- Para aclarar los factores que contribuyen a la mayor actividad catalítica.
Principales métodos:
- Se empleó la espectroscopia de la transformación de Fourier de reflexión difusa infrarroja in situ (DRIFTS).
- El análisis cinético y el modelado computacional se utilizaron para comprender la vía de reacción.
Principales resultados:
- El metanol se adsorbe disociativamente en el soporte de nanoceria.
- Las especies metoxicas se difunden a sitios Pt individuales para la deshidrogenación.
- El monóxido de carbono (CO) de enlace débil se forma como producto.
Conclusiones:
- La mayor actividad de Pt1/CeO2 se atribuye a la fácil adsorción de metanol en el soporte de ceria.
- Las interacciones entre el metal y el soporte adaptan las propiedades electrónicas de los sitios Pt individuales.
- Estos factores contribuyen colectivamente al rendimiento superior en la descomposición del metanol.
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