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Inversión de la selectividad de hidrogenación con alta actividad a través de interacciones inducidas por la reacción

Hui Xin¹, Le Lin¹, Rongtan Li^1,2

¹State Key Laboratory of Catalysis, iChEM, Dalian Institute of Chemical Physics, Chinese Academy of Science, Dalian 116023, P. R. China.

Journal of the American Chemical Society

|March 8, 2022

Resumen

Se logró una fuerte interacción con el soporte metálico (SMSI) a bajas temperaturas durante la hidrogenación con CO2. Esta encapsulación dinámica de nanopartículas de rutenio por capas de óxido de molibdeno produjo selectivamente CO con alta actividad y estabilidad.

Área de la Ciencia:

Catálisis
Ciencias de los materiales
Química de las superficies

Sus antecedentes:

La interacción fuerte entre metal y soporte (SMSI) requiere típicamente altas temperaturas (≥500 °C) para la encapsulación de nanopartículas metálicas por materiales de soporte.
Este estado clásico de SMSI a menudo conduce a una reducción del rendimiento catalítico debido a la obstrucción del sitio activo.

Objetivo del estudio:

Investigar la formación de SMSI a baja temperatura en un catalizador Ru-MoO3 durante la hidrogenación con CO2.
Comprender el mecanismo de la encapsulación dinámica y su efecto sobre la selectividad y la actividad catalítica.

Principales métodos:

Se utilizó un catalizador Ru-MoO3 para la hidrogenación de CO2 a 250 °C.
Se analizó la formación de la estructura encapsuladora de Ru@MoO3 utilizando condiciones de reacción in situ.
Investigó la reversibilidad del estado de SMSI a través del tratamiento con O2.

Principales resultados:

Estado SMSI alcanzado a una baja temperatura de 250 °C utilizando gas de hidrogenación CO2.
Se ha demostrado la hidrogenación selectiva de CO2 a CO con una selectividad superior al 99,0%, en sustitución de la selectividad del CH4 del 100% en catalizadores de Ru frescos.
Se ha observado una excelente actividad catalítica y estabilidad a largo plazo para la producción de CO.
Se ha demostrado que la capa de óxido de encapsulación puede eliminarse mediante tratamiento con O2, volviendo a la metanización.

Conclusiones:

La encapsulación dinámica de los nanocatalizadores metálicos puede generarse in situ durante las reacciones.
La formación de SMSI a baja temperatura mejora el rendimiento catalítico y la selectividad del producto.
Este enfoque ofrece una vía para controlar el comportamiento del catalizador para la síntesis de productos específicos.

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