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La red de enlaces de hidrógeno inducida por ligandos de superficie cambia la selectividad de la semi-hidrogenación

Weijie Zhang¹, Ruixuan Qin^1,2, Gang Fu¹

¹State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, National & Local Joint Engineering Research Center for Preparation Technology of Nanomaterials, and National Engineering Laboratory for Green Chemical Productions of Alcohols-Ethers-Esters, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.

Journal of the American Chemical Society

|April 28, 2023

Resumen

Los investigadores mejoraron la selectividad del catalizador utilizando nanohojas de paladio recubiertas de cisteamina. Una nueva transformación zwitteriónica crea una red de enlaces de hidrógeno, mejorando la hidrogenación de alquinos sobre la hidrogenación de alceno.

Área de la Ciencia:

Catálisis heterogénea
Química de las superficies
Ciencias de los nanomateriales

Sus antecedentes:

El ajuste de las interfaces metal-ligando es clave para la optimización del catalizador.
La mejora de la selectividad a través de la modificación orgánica de los catalizadores sigue siendo un reto.
Los catalizadores de paladio son ampliamente utilizados, pero a menudo carecen de selectividad.

Objetivo del estudio:

Desarrollar una nueva estrategia de modificación de ligandos para mejorar la selectividad del catalizador.
Investigar el mecanismo detrás de la mejora de la selectividad en la hidrogenación catalizada por paladio.
Para crear un catalizador altamente selectivo y duradero para la hidrogenación de alquinos.

Principales métodos:

Preparación de nanohojas de paladio ultrafinas recubiertas con cisteamina.
Hidrogenación catalítica de alquinas terminales mediante el catalizador de paladio modificado.
Caracterización in situ para estudiar la transformación de la interfaz en condiciones de reacción.

Principales resultados:

Las nanohojas de paladio recubiertas de cisteamina mostraron una excelente selectividad y durabilidad en la hidrogenación alquina.
Se produjo una transformación zwitteriónica en la interfaz de paladio bajo H2, formando una red rígida de enlaces de hidrógeno.
Esta red favoreció la hidrogenación de alquino sobre la hidrogenación de alqueno, superando los efectos estéricos tradicionales.

Conclusiones:

La modificación de ligandos a través de la transformación zwitteriónica ofrece un nuevo enfoque para mejorar la selectividad del catalizador.
El catalizador desarrollado proporciona un método práctico para mejorar tanto la selectividad como la actividad en las reacciones de hidrogenación.
Este estudio introduce un nuevo concepto de efecto estérico en la química de la coordinación superficial.

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