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Observación sobre los cambios en el microambiente de los catalizadores dinámicos en la reducción de CO2 ácido

Heming Liu¹, Tian Yan², Shendong Tan²

¹Shenzhen Geim Graphene Center, Tsinghua-Berkeley Shenzhen Institute & Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, P. R. China.

Journal of the American Chemical Society

|February 19, 2024

Resumen

Este estudio aborda la degradación del catalizador en la reducción electroquímica ácida de CO2 (CO2RR). Una nueva estrategia de cronoamperometría de pulso mejora significativamente la estabilidad del catalizador durante 100 horas, mejorando el rendimiento de CO2RR.

Área de la Ciencia:

La electroquímica
Catálisis
Ciencias de los materiales

Sus antecedentes:

Los electrolitos ácidos ofrecen soluciones a los problemas de alcalinidad en la reducción de CO2, pero presentan desafíos debido a la degradación del catalizador.
Asegurar la estabilidad del catalizador es fundamental para la viabilidad de la reducción electroquímica de CO2 en medios ácidos.

Objetivo del estudio:

Investigar los cambios en el microambiente de los catalizadores dinámicos basados en Bi durante la CO2RR ácida.
Desarrollar una estrategia de cronoamperometría de pulso (CA) para mejorar la estabilidad del catalizador en CO2RR ácido.

Principales métodos:

Se utilizaron mapas de fluorescencia in situ para observar los cambios de pH locales.
Se empleó la espectroscopia Raman in situ para analizar la evolución de la estructura del agua interfacial.
Desarrolló y aplicó una estrategia de CA de pulso para la reactivación del catalizador.

Principales resultados:

Cambios dinámicos demostrados en el microambiente, incluidos cambios de pH locales y estructuras de agua alteradas, en la interfaz del catalizador.
Se demostró que la carga superficial del catalizador influye en la adsorción de iones (K + y protones), afectando el pH local y la adsorción intermedia.
Logró una mejora de dos órdenes de magnitud en la estabilidad ácida de CO2RR, manteniendo el rendimiento durante 100 horas utilizando la estrategia de CA de pulso.

Conclusiones:

Las dinámicas del microambiente afectan significativamente la estabilidad de los catalizadores en el CO2RR ácido.
La estrategia de CA de pulso desarrollada reactiva efectivamente los catalizadores y mejora drásticamente la estabilidad operativa.
Proporciona información crucial para el diseño de catalizadores robustos para la reducción electroquímica estable de CO2 en entornos ácidos.

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