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Oxidación selectiva del metano a metanol en ZnO/Cu2O/Cu111) Catalizadores: comportamientos múltiples dependientes del
Erwei Huang1, Ivan Orozco1, Pedro J Ramírez2,3
1Department of Chemistry, Stony Brook University, Stony Brook, New York 11794, United States.
Journal of the American Chemical Society
|November 4, 2021
Resumen
Los investigadores han desarrollado un eficiente catalizador de ZnO/Cu2O/Cu111 para la conversión directa de metano en metanol. Este catalizador logra una selectividad de ~ 30% a 450 K sin agua y más del 80% con agua, ofreciendo una nueva estrategia para la reformación del metano.
Área de la Ciencia:
- Catálisis
- Ciencias de los materiales
- Ingeniería Química
Sus antecedentes:
- La conversión directa de metano en metanol es un objetivo clave para la utilización del abundante gas natural.
- Los catalizadores heterogéneos existentes a menudo requieren la adición de agua y altas temperaturas para una conversión significativa.
Objetivo del estudio:
- Desarrollar e investigar un catalizador eficaz para la conversión directa de metano en metanol a temperaturas más bajas.
- Comprender los mecanismos catalíticos y los sitios activos involucrados en el proceso.
Principales métodos:
- Pruebas de reactores
- Microscopía de túnel de barrido (STM)
- Espectroscopia de fotoemisión de rayos X bajo presión ambiente (AP-XPS)
- Cálculos funcionales de la densidad (DFT)
- Simulaciones cinéticas de Montecarlo
Principales resultados:
- El catalizador ZnO/Cu2O/Cu111 activa el metano a temperatura ambiente.
- La síntesis de metanol a partir de metano y oxígeno alcanzó una selectividad de ~ 30% a 450 K sin agua.
- La adición de agua aumentó la selectividad del metanol a más del 80% mediante la activación de diferentes sitios en la superficie.
Conclusiones:
- La estructura única de las islas de ZnO en Cu2O/Cu111) crea diversos sitios activos.
- Los sitios de la etapa ZnO-Cu2O son cruciales para la síntesis de metanol a través de la disociación de enlaces O-O.
- Los sitios defectuosos de ZnO con vacíos de Zn son muy eficaces para la conversión de metano en presencia de agua.
- La identificación del comportamiento dependiente del sitio proporciona una estrategia para diseñar catalizadores eficientes de reformación de metano.
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