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Promotores básicos Termodinámica de impacto y especiación del catalizador en la hidrogenación de carbonilo homogéneo
Wenjun Yang1, Tejas Y Kalavalapalli1, Annika M Krieger1
1Inorganic Systems Engineering Group, Department of Chemical Engineering, Faculty of Applied Sciences, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands.
Journal of the American Chemical Society
|April 27, 2022
Resumen
Los promotores de reacción en la hidrogenación homogénea pueden ajustar indirectamente la termodinámica, permitiendo reacciones desfavorables. Este estudio muestra que los promotores controlan la especiación del catalizador y las energías libres de reacción, remodelando el paisaje catalítico.
Área de la Ciencia:
- Catálisis homogénea
- Química organometálica
- La Termodinámica Química
Sus antecedentes:
- Los aditivos y promotores son cruciales en la catálisis homogénea, generalmente estudiados por su reactividad química directa.
- A menudo se pasa por alto su influencia indirecta en la termodinámica de la reacción.
- La inhibición del producto es un desafío común en procesos catalíticos como la hidrogenación de ésteres.
Objetivo del estudio:
- Investigar el papel indirecto de los promotores de reacción en la catálisis de hidrogenación homogénea.
- Demostrar cómo los promotores pueden modular la termodinámica de la reacción y superar las transformaciones desfavorables.
- Explorar el impacto de los promotores en la especiación del catalizador y el control termodinámico.
Principales métodos:
- Se utilizó una serie de catalizadores de pinzas de manganeso (Mn) para la hidrogenación de ésteres.
- Se ha investigado el efecto de los aditivos de base de alcóxidos (promotores) en el rendimiento del catalizador y la termodinámica de la reacción.
- Experimentalmente varió la concentración del promotor para observar cambios en la especiación del catalizador y las energías libres.
Principales resultados:
- Se encontró que los promotores de bases de alcósidos ajustaban las constantes de equilibrio de las transformaciones clave, incluso sin participación química directa.
- La variación de la concentración del promotor permitió el control de la especiación del catalizador.
- Se lograron cambios sustanciales en las energías libres estándar de los pasos del ciclo catalítico, lo que demuestra el control externo sobre la termodinámica de la reacción.
Conclusiones:
- Los promotores de reacción pueden influir indirectamente en la catálisis al alterar la termodinámica de la reacción.
- Los promotores pueden permitir reacciones termodinámicamente desfavorables en la hidrogenación homogénea.
- Los promotores son parte integral del medio de reacción, capaces de remodelar el paisaje termodinámico y mejorar el rendimiento catalítico.
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