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Identificación de la catálisis del oro en un solo lugar en la clorhidratación del acetileno
Grazia Malta1, Simon A Kondrat1, Simon J Freakley1
1Cardiff Catalysis Institute, School of Chemistry, Cardiff University, Main Building, Park Place, Cardiff CF10 3AT, UK.
Science (New York, N.Y.)
|April 1, 2017
Resumen
La forma activa de los catalizadores de oro en la clorhidratación del acetileno involucra especies de oro catiónico de un solo sitio. Su actividad depende del equilibrio de los estados de oxidación oro (I) y oro (III), lo que sugiere un mecanismo redox.
Área de la Ciencia:
- Catálisis
- Ciencias de los materiales
- Química inorgánica
Sus antecedentes:
- La clorhidratación del acetileno es un proceso industrial clave.
- La forma activa precisa de los catalizadores de oro en condiciones de reacción sigue siendo objeto de debate.
- Comprender las especies activas es crucial para la optimización del catalizador.
Objetivo del estudio:
- Identificar las especies activas de oro en los catalizadores de oro/carbono (Au/C) durante la clorhidratación del acetileno.
- Para correlacionar la actividad del catalizador con los estados de oxidación del oro.
- Para aclarar el mecanismo catalítico.
Principales métodos:
- Se empleó la espectroscopia de estructura fina de absorción de rayos X in situ (XAFS).
- Se estudiaron los catalizadores oro/carbono (Au/C) en condiciones reales de reacción.
- Se utilizó el modelado computacional para apoyar las propuestas mecanicistas.
Principales resultados:
- Se encontró que los catalizadores altamente activos contenían entidades de oro catiónico de un solo sitio.
- La actividad del catalizador mostró una correlación directa con la proporción de especies de oro (I) y oro (III).
- Los catalizadores Au/C fueron identificados como análogos de catalizadores de oro homogéneos de un solo sitio.
Conclusiones:
- La forma activa del oro en estos catalizadores es el oro catiónico de un solo sitio.
- Se propone un mecanismo catalítico que involucra una pareja redox oro-oro.
- Estos hallazgos proporcionan información sobre el diseño de eficientes catalizadores de clorhidratación a base de oro.
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