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Autoensamblaje molecular en redes covalentes conductivas para la electrorreducción selectiva de nitrato a amoníaco
Feiqing Sun1, Yifan Gao1, Mengjie Li1
1Department of Chemistry, Zhejiang University, Hangzhou 310058, China.
Journal of the American Chemical Society
|September 21, 2023
Resumen
Este estudio presenta un nuevo catalizador de hierro basado en hidrogel para la síntesis electroquímica eficiente de amoníaco a partir de nitrato. El catalizador logra una alta selectividad mediante el control del microambiente hidrofóbico local, suprimiendo las reacciones secundarias.
Área de la Ciencia:
- La electroquímica
- Ciencias de los materiales
- Catálisis
Sus antecedentes:
- La reducción electroquímica de nitrato es una vía prometedora para la síntesis de amoníaco.
- El microambiente alrededor de los catalizadores tiene un impacto significativo en el rendimiento electrocatalítico.
- El desarrollo de catalizadores selectivos para la producción de amoníaco sigue siendo un desafío.
Objetivo del estudio:
- Desarrollar un catalizador de hierro molecular autoensamblado integrado en un hidrogel conductor para la síntesis selectiva de amoníaco.
- Investigar el papel del microambiente local en el control de la selectividad electrocatalítica.
- Lograr una alta eficiencia y una producción continua de amoníaco a partir de nitrato.
Principales métodos:
- Fabricación de un hidrogel conductor independiente que incorpora un catalizador molecular de hierro.
- Caracterización electroquímica de la reducción de nitratos en medios acuosos.
- Análisis de la selectividad del amoníaco y las densidades de corriente bajo diferentes sesgos.
- Investigación de la hidrofobia del hidrogel y su efecto sobre la electro-deshidratación.
Principales resultados:
- El catalizador de hidrogel integrado produjo selectivamente amoníaco a partir de nitrato con eficiencias cercanas a la unidad.
- Se mantuvo una alta selectividad del amoníaco (89-98%) bajo varios sesgos negativos.
- La hidrofobia del sustrato policarbazol suprimió la reducción de protones a través de la electro-deshidratación en medios ácidos.
- Se logró una producción continua de amoníaco durante más de 100 horas a altas densidades de corriente.
Conclusiones:
- La construcción de una superficie hidrofóbica interna dentro de los electrocatalizadores es crucial para controlar la selectividad en medios acuosos.
- El hidrogel electrocatalítico desarrollado ofrece una plataforma robusta para la síntesis eficiente y selectiva de amoníaco.
- Este trabajo pone de relieve la importancia de la ingeniería del microambiente catalizador para optimizar los procesos electroquímicos.
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