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Control de la selectividad del catalizador metálico a través de interacciones moleculares no covalentes específicas

Karl R Kahsar¹, Daniel K Schwartz, J Will Medlin

¹Department of Chemical and Biological Engineering, University of Colorado Boulder , Boulder, Colorado 80309-0596, United States.

Journal of the American Chemical Society

|December 11, 2013

Resumen

Los investigadores utilizaron monocapas autoensambladas (SAM) en catalizadores de platino para controlar las reacciones químicas. Este método mejoró la selectividad para los productos deseados mediante la orientación de las moléculas reactivas, mejorando el rendimiento del catalizador.

Área de la Ciencia:

La catálisis es la catálisis.
Química de las superficies.
Química orgánica es la química orgánica.

Sus antecedentes:

Mejorar la especificidad del catalizador es crucial para una síntesis química eficiente.
Las interacciones no covalentes ofrecen una vía para controlar la geometría de unión de los reactivos.
Las monocapas autoensambladas de tiolato (SAM) pueden funcionalizar las superficies del catalizador.

Objetivo del estudio:

Investigar el uso de SAMs de tiolato estructurado en catalizadores Pt/Al2O3.
Para mejorar la selectividad en la hidrogenación de cinamaldehído a través de la orientación dirigida del reactivo.
Para diferenciar entre las interacciones no específicas y específicas en la sintonización de la selectividad catalítica.

Principales métodos:

Aplicación de monocapas autoensambladas de tiolato específicamente estructuradas (SAM) a los catalizadores Pt/Al2O3.
Conducir reacciones de hidrogenación de cinamaldehído y un aldehído insaturado no fenilado.
Utilizando la espectroscopia infrarroja para analizar la orientación del reactivo en la superficie del catalizador.

Principales resultados:

Los SAM fenilados orientan selectivamente el cinnamaldehído a través del apilamiento aromático, mejorando la selectividad para el alcohol cinnamyl.
Las interacciones específicas ajustaron la selectividad sin reducir la velocidad de reacción para la formación del producto deseado.
Tanto los efectos superficiales no específicos como los efectos cercanos a la superficie específicos de los ligandos contribuyeron a mejorar la selectividad.

Conclusiones:

Los SAM estructurados pueden controlar con precisión la orientación del reactivo en catalizadores sólidos.
Las interacciones de apilamiento aromático proporcionan un método sintonizable para mejorar la selectividad catalítica.
Los SAM de tiol ofrecen un mecanismo dual para mejorar la selectividad de reacción a través de interacciones superficiales generales y específicas.

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