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Los conjuntos Pt de pocos átomos permiten una deshidrogenación catalítica eficiente para la producción de hidrógeno
Yuchen Deng1, Yu Guo1, Zhimin Jia2,3
1Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
Journal of the American Chemical Society
|February 2, 2022
Resumen
Los catalizadores de un solo átomo (SAC) son inactivos para la deshidrogenación del ciclohexano. El rendimiento óptimo se logra mediante conjuntos de platino de pocos átomos, no de átomos individuales, para una producción eficiente de hidrógeno.
Área de la Ciencia:
- Catálisis heterogénea
- Ciencias de los materiales
- Química de las superficies
Sus antecedentes:
- La identificación de sitios activos es crucial para el diseño de catalizadores metálicos eficientes.
- Los catalizadores de un solo átomo (SAC) ofrecen una alta dispersión de metales y utilización de átomos.
- La deshidrogenación del ciclohexano es clave para el transporte de hidrógeno.
Objetivo del estudio:
- Investigar la actividad catalítica de los catalizadores de un solo átomo de platino (SAC) frente a los conjuntos de pocos átomos para la deshidrogenación del ciclohexano.
- Determinar el tamaño óptimo del grupo metálico para un rendimiento catalítico eficiente en esta reacción.
Principales métodos:
- Síntesis y caracterización de catalizadores de platino con diferentes tamaños de racimos metálicos (de un solo átomo a conjuntos de pocos átomos).
- Evaluación de la actividad catalítica para la deshidrogenación del ciclohexano.
- Análisis de las relaciones estructura-rendimiento.
Principales resultados:
- Los SAC de platino no mostraron actividad en la deshidrogenación del ciclohexano, a pesar de su alta eficiencia atómica.
- Los catalizadores con conjuntos de platino de pocos átomos totalmente expuestos (número de coordinación ~ 2) exhibieron un rendimiento óptimo.
- La actividad superior de los conjuntos de pocos átomos está vinculada a un centro de banda d alto y múltiples sitios metálicos.
Conclusiones:
- El diseño óptimo del catalizador para la deshidrogenación del ciclohexano implica conjuntos de pocos átomos, no átomos individuales.
- Los conjuntos de pocos átomos proporcionan un equilibrio de propiedades electrónicas y sitios vecinos para una catálisis eficiente.
- Este hallazgo pone en tela de juicio la aplicabilidad universal de los SAC y pone de relieve la importancia de los efectos de conjunto.
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