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Lograr una hidrogenación selectiva "verdadera" mediante el tratamiento con CO del catalizador Pt/TiO2

Fengwei Zhang¹, Feng Hong², Xuetao Qin³

¹Institute of Crystalline Materials, Institute of Molecular Science, Shanxi Key Laboratory for the Green Catalysis Synthesis of Coal-Based Value-Added Chemicals, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, P. R. China.

Journal of the American Chemical Society

|July 21, 2025

Resumen

Los investigadores han desarrollado un nuevo tratamiento térmico del gas CO para los catalizadores Pt/TiO2, que permite la hidrogenación selectiva de los grupos nitro (-NO2) mientras se conservan los enlaces dobles carbono-carbono (-C=C). Este avance aborda los desafíos clave en la catálisis industrial.

Área de la Ciencia:

Catálisis heterogénea
Ciencias de los materiales
Síntesis orgánica

Sus antecedentes:

La hidrogenación selectiva es crucial en la química industrial, pero es un desafío debido a la variación de la reactividad del grupo funcional.
Los métodos existentes a menudo requieren un control estricto, lo que limita la flexibilidad y complica la purificación.
La conversión de grupos menos reactivos (por ejemplo, nitro) en grupos más reactivos (por ejemplo, alquenos) es particularmente difícil.

Objetivo del estudio:

Desarrollar un sistema catalítico para la verdadera hidrogenación selectiva de los grupos nitro sobre los enlaces dobles carbono-carbono.
Superar las limitaciones de las actuales estrategias preferenciales de hidrogenación.
Mejorar la flexibilidad operativa y simplificar la separación de productos en los procesos industriales de hidrogenación.

Principales métodos:

Se sintetizó un catalizador de platino apoyado en dióxido de titanio (Pt / TiO2).
El catalizador se sometió a un proceso de tratamiento térmico con gas de monóxido de carbono (CO).
Se realizaron estudios mecanicistas para aclarar la naturaleza de los sitios activos y las vías de reacción.

Principales resultados:

El catalizador Pt/TiO2 tratado con CO hidrogena selectivamente el grupo nitro (-NO2) conservando el enlace alqueno (-C=C).
Se identificaron dos sitios activos distintos: sitios Pt de un solo átomo para la hidrogenación de alquenos y sitios de nanopartículas TiO_x/Pt para la hidrogenación de grupos nitro.
Los sitios Pt de un solo átomo exhiben interacciones rápidas y reversibles de hidrógeno, lo que lleva a una aparente no reactividad hacia los alquenos en condiciones específicas.

Conclusiones:

Se demostró un método robusto para la hidrogenación selectiva de nitrogrupos en presencia de alquenos.
El catalizador tratado ofrece una estrategia versátil para el diseño de sistemas catalíticos altamente selectivos.
Este descubrimiento tiene implicaciones significativas para el avance de las aplicaciones catalíticas industriales.

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