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Par frustrado de Lewis confinado por el zeotipo y su papel en la hidrogenación catalizadora

Mengyuan Li^1,2, Yihan Ye^1,2, Bing Bai^1,2

¹State Key Laboratory of Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, 457 Zhongshan Road, Dalian 116023, P. R. China.

Journal of the American Chemical Society

|April 23, 2025

Resumen

Este estudio proporciona la primera evidencia experimental de sitios frustrados de pares de Lewis (FLP) en zeotipos, cruciales para las reacciones de hidrogenación sin metales. Los sitios ácidos más débiles mejoran la formación de FLP y la actividad catalítica en la hidrogenación de etileno.

Área de la Ciencia:

Catálisis
Ciencias de los materiales
Química Física

Sus antecedentes:

Los estudios teóricos predijeron la formación de pares de Lewis frustrados (FLP) en zeolitas / zeotipos para la activación de enlaces.
Faltan pruebas experimentales y comprensión mecanicista de las funciones del FLP en la hidrogenación.

Objetivo del estudio:

Proporcionar pruebas experimentales y un principio general para la formación del sitio de FLP en los zeotipos.
Investigar la influencia de la topología de la zeolita y la resistencia ácida en la formación de FLP.
Aclarar el papel de los sitios de FLP en la hidrogenación del etileno.

Principales métodos:

Investigaciones experimentales combinadas con cálculos basados en la teoría de la densidad funcional (DFT).
Estudió el efecto de la fuerza del ácido de Brønsted y la topología del zeotipo en la formación de FLP.
Actividad catalítica evaluada en la hidrogenación del etileno.

Principales resultados:

Se ha demostrado la formación de FLP a través de la transferencia de H+ de sitios débiles de ácido de Brønsted a especies carbonáceas confinadas.
Sitios de FLP identificados como centros activos para la hidrogenación del etileno.
Se encontró una correlación inversa entre la actividad de FLP y la fuerza del ácido de Brønsted.
Se demostró que los sitios ácidos más débiles mejoran la adsorción de C2H4 y la activación de H2.

Conclusiones:

Se estableció un principio general para la formación del sitio de FLP en los zeotipos.
Proporcionó conocimientos mecanicistas sobre la hidrogenación de las olefinas libres de metales sobre las zeolitas/zeotipos.
Destacó el potencial de los catalizadores de zeotipo adaptados para aplicaciones de hidrogenación eficientes y heterogéneas de FLP.

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