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Eliminación de agentes tensioactivos para catalizadores de nanocristales coloidales mediados por carbenos

Perrin Godbold¹, Grayson Johnson¹, Akachukwu D Obi¹

¹Department of Chemistry, University of Virginia, Charlottesville, Virginia 22904, United States.

Journal of the American Chemical Society

|February 11, 2021

Resumen

Desarrollamos un nuevo método utilizando carbenos N-heterocíclicos (NHC) para limpiar las superficies nanocristalinas para mejorar la catálisis. Este enfoque mejora la actividad catalítica para reacciones electroquímicas importantes.

Área de la Ciencia:

Ciencias de los materiales
Nanotecnología
Catálisis

Sus antecedentes:

Los nanocristales sintetizados coloidalmente a menudo requieren la eliminación de surfactante para un rendimiento óptimo.
Los métodos de limpieza existentes pueden dañar la estructura y la morfología del nanocristal.
La pasivación de la superficie por los estabilizadores dificulta la aplicación del nanocristal en la catálisis.

Objetivo del estudio:

Desarrollar un método fácil y eficaz para eliminar los tensioactivos de los nanocristales.
Mejorar la actividad catalítica de los nanocristales a través de la activación superficial.
Para validar la estrategia en varios nanocristales de metales nobles (Pt, Pd, Au).

Principales métodos:

Intercambio de ligandos utilizando carbenos N-heterocíclicos (NHC) para reemplazar los tensioactivos.
Protonación mediada por ácido de los ligandos NHC para una limpieza eficiente de la superficie.
Caracterización de la morfología y estructura del nanocristal después de la limpieza.
Evaluación de la actividad catalítica en las reacciones electroquímicas.

Principales resultados:

Eliminación exitosa de los estabilizadores de fosfina fuertemente unidos de los nanocristales Pt, Pd y Au.
Preservación de la morfología y estructura uniformes del nanocristal después de la limpieza.
Actividades catalíticas significativamente mejoradas en la oxidación del glicerol y la reducción de CO2 en comparación con otros métodos.
Se ha demostrado una amplia eficacia en diferentes nanocristales de metales nobles.

Conclusiones:

El intercambio de ligandos basado en carbenos N-heterocíclicos ofrece una estrategia de activación superficial eficiente para los nanocristales.
Este método permite el uso de bibliotecas de nanocristales sintetizadas coloidalmente para la catálisis.
El enfoque es ampliamente aplicable a varios sistemas de nanocristales y aplicaciones que requieren superficies limpias.

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