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Hidrólisis del amoníaco-borano sobre el nanocatalizador Ni/ZIF-8: alta eficiencia, mecanismo y liberación controlada

Changlong Wang^1,2, Jimena Tuninetti³, Zhao Wang⁴

¹Laboratoire de Chimie de Coordination , UPR CNRS 8241, Toulouse 31077 Cedex, France.

Journal of the American Chemical Society

|August 2, 2017

Resumen

Las nanopartículas de níquel con plantilla de imidazolato zeolítico ofrecen una catálisis eficiente y libre de ligandos para la hidrólisis de amoniaco y boro, superando a muchos sistemas de nanopartículas de metales no nobles y nobles. Este avance permite la producción controlada de hidrógeno.

Área de la Ciencia:

Ciencias de los materiales
Nanotecnología
Catálisis

Sus antecedentes:

Las nanopartículas de metales no nobles son difíciles de sintetizar y estabilizar, lo que limita sus aplicaciones catalíticas.
El desarrollo de catalizadores de metales no nobles eficientes y estables es crucial para la química sostenible.

Objetivo del estudio:

Preparación y comparación de nanopartículas de metales de transición tardías de primera fila, libres de ligandos y con eficiencia catalítica, utilizando una plantilla de imidazolato zeolítico (ZIF-8).
Investigar los principios catalíticos en la hidrólisis de amoníaco y boro y optimizar la producción de hidrógeno.

Principales métodos:

Utilizó ZIF-8 como una plantilla de marco metálico-orgánico (MOF) para la síntesis de nanopartículas.
El rendimiento catalítico evaluado en la hidrólisis de amoníaco y boro.
Se han realizado estudios mecanicistas, incluidos los efectos cinéticos de los isótopos, para determinar el paso determinante de la velocidad.

Principales resultados:

Las nanopartículas de níquel templadas exhibieron la mayor actividad catalítica entre los metales de transición tardía de primera fila probados.
Se logró una frecuencia de rotación total de 85,7 molH2 molcat-1 min-1 para las nanopartículas de Ni a temperatura ambiente.
Demostró un rendimiento superior al de los anteriores sistemas de nanopartículas de metales no nobles y algunos sistemas de metales nobles.

Conclusiones:

La plantilla ZIF-8 permite la preparación de nanopartículas de metales no nobles altamente activas y estables.
La escisión del enlace O-H a través de la adición oxidativa es el paso que determina la velocidad en la hidrólisis de amoniaco y boro.
Desarrolló una estrategia para el control "on-off" de la producción de hidrógeno basada en conocimientos mecanicistas.

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