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La oxidación electrocatalítica del amoníaco en nitrato se produce en NiOOH con huecos OH/O

Vi Thuy Thi Phan¹, Quy P Nguyen², Bin Wang²

¹Department of Chemistry, University of Saskatchewan, Saskatoon, SK S7N 5C9, Canada.

Journal of the American Chemical Society

|March 13, 2025

Resumen

Este estudio aclara las vías de electrooxidación del amoníaco (AOR) en los electrodos de níquel. Identifica los sitios activos y muestra que la producción de nitrito/nitrato depende del potencial del electrodo, lo que ayuda al diseño del catalizador para el tratamiento de aguas residuales y el almacenamiento de energía.

Área de la Ciencia:

La electroquímica
Catálisis
Ciencias de los materiales

Sus antecedentes:

La electrooxidación del amoníaco (AOR) es clave para el tratamiento de aguas residuales y el almacenamiento de energía.
La comprensión de las vías de reacción AOR y los sitios activos sigue siendo un desafío.

Objetivo del estudio:

Elucidar los intermedios dependientes de potencial, los sitios activos y las vías de AOR en los electrodos de Ni.
Investigar el papel de las vacantes de OH/O en NiOOH en AOR.

Principales métodos:

Espectroscopia de absorción infrarroja atenuada total mejorada por superficie (ATR-SEIRAS) y teoría funcional de la densidad (DFT).
Se utilizó la espectroscopia de fotoelectrones de rayos X (XPS) para identificar los sitios activos.

Principales resultados:

DFT identificó las zonas de vacío de OH/O en NiOOH como zonas activas para la oxidación completa del amoníaco en nitrato.
La selectividad de la producción de nitrito y nitrato depende del potencial.
La liberación de nitrito y nitrato adsorbidos se facilita a bajos potenciales.

Conclusiones:

El estudio proporciona una comprensión mecanicista del AOR en catalizadores basados en Ni.
Los resultados pueden orientar el diseño de catalizadores eficientes para aplicaciones AOR.
Las vías dependientes del potencial y la identificación del sitio activo son cruciales para optimizar el rendimiento de AOR.

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