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Hidroformilación bifuncional en catalizadores heterogéneos de par de sitios Rh-WOx
Insoo Ro1,2,3, Ji Qi1,3, Seungyeon Lee3,4
1Department of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, CA, USA.
Nature
|September 7, 2022
Resumen
Los sitios de pares de óxido de rodio-tungsteno dispersos atómicamente (Rh-WOx) permiten la catálisis bifuncional para la hidroformilación del etileno. Estos catalizadores respaldados muestran una alta selectividad y actividad, imitando a los catalizadores homogéneos para aplicaciones industriales.
Área de la Ciencia:
- Catálisis heterogénea
- Ciencias de la superficie
- Química orgánica de los metales
Sus antecedentes:
- Los sitios activos bifuncionales son cruciales para las reacciones catalizadas por metales, facilitando pasos distintos en un ciclo catalítico.
- Aunque está establecido para catalizadores homogéneos, aclarar estos sitios en metales soportados es un desafío debido a la complejidad estructural y la reconstrucción dinámica.
- Los catalizadores metálicos soportados a menudo incluyen interfaces de óxido de metal como posibles sitios bifuncionales.
Objetivo del estudio:
- Superar los desafíos en el estudio de mecanismos bifuncionales en catalizadores metálicos con soporte.
- Para sintetizar y caracterizar un sistema de modelo simplificado: sitios de pares de óxido de rodio-tungsteno (Rh-WOx) dispersos atómicamente.
- Para correlacionar la cinética experimental con las simulaciones teóricas de un mecanismo de reacción bifuncional.
Principales métodos:
- Síntesis de catalizadores de par de sitios Rh-WOx con soporte y dispersión atómica.
- Experimentos de hidroformilación de etileno en la fase gaseosa.
- Las primeras simulaciones microkinéticas basadas en principios se correlacionan con la cinética experimental.
- Caracterización de la estructura del sitio activo y el rendimiento catalítico.
Principales resultados:
- Los sitios del par Rh-WOx catalizan la hidroformilación del etileno a través de un mecanismo bifuncional.
- El mecanismo implica la reducción de WOx asistida por Rh, la transferencia de etileno de WOx a Rh y la disociación de H2 en la interfaz.
- Se logra una selectividad > 95% con una tasa de formación de producto de 0,1 g de propanal cm−3 h−1.
- Se ha demostrado la idoneidad del modelado de campo medio para este sistema simplificado de par de sitios.
Conclusiones:
- Los sitios de pares de óxidos soportados pueden permitir efectivamente mecanismos de reacción bifuncionales.
- Estos sitios ofrecen una alta actividad y selectividad, comparables a los catalizadores homogéneos.
- Este enfoque proporciona una vía para diseñar catalizadores heterogéneos avanzados para procesos industriales.
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