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Aplicación de la dispersión nuclear hacia adelante como herramienta para la caracterización de las moléculas de FeN

Nils Heppe¹, Charlotte Gallenkamp^1,2, Rifael Z Snitkoff-Sol³

¹Catalysts and Electrocatalysts, Eduard-Zintl-Institute of Inorganic and Physical Chemistry, Department of Chemistry, Technical University Darmstadt, Otto-Berndt-Str. 3, 64287 Darmstadt, Germany.

Journal of the American Chemical Society

|April 17, 2024

Resumen

La dispersión nuclear hacia adelante (NFS) es una nueva técnica de sincrotrón para el estudio de electrocatalizadores. Ofrece mediciones más rápidas y un análisis mejorado del sitio de hierro en comparación con la espectroscopia de Mössbauer, ayudando al diseño del catalizador.

Área de la Ciencia:

* Ciencias de los materiales
* La electroquímica
* Espectroscopia

Sus antecedentes:

* La dispersión nuclear hacia adelante (NFS, por sus siglas en inglés) es una técnica basada en sincrotrones.
* Utiliza el efecto de resonancia nuclear sin retroceso, similar a la espectroscopia de Mössbauer.
* NFS ofrece ventajas en la velocidad y la discriminación del sitio para ciertos elementos como el hierro.

Objetivo del estudio:

* Introducir y demostrar el NFS para los estudios in situ y operando de las reacciones electrocatalíticas.
* Aplicar el NFS para investigar el mecanismo de evolución del hidrógeno de los catalizadores de porfirina de hierro.
* Para comparar el NFS con la espectroscopia de Mössbauer para la caracterización del catalizador.

Principales métodos:

Espectroscopía de dispersión nuclear avanzada (NFS) empleada "in situ" y "operando".
* Se utilizaron técnicas de rayos X basadas en sincrotrones.
* Combinación de datos experimentales NFS con predicciones teóricas de datos espectroscópicos.

Principales resultados:

* Demostró la capacidad de NFS para la adquisición de datos más rápida y la discriminación de sitios de hierro mejorada.
* Se aplicó con éxito NFS para estudiar un catalizador de porfirina de hierro inmovilizado.
* Se identificó un intermediario clave en el mecanismo de reacción de la evolución del hidrógeno.

Conclusiones:

El NFS es una técnica potente y accesible para la investigación de la electrocatálisis "in situ" y "operando".
* El estudio aclaró el mecanismo de evolución del hidrógeno de los catalizadores de porfirina de hierro.
* Los hallazgos pueden orientar la optimización de catalizadores moleculares y de metal-nitrógeno-carbono (MNC).

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