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Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase
Published on: December 4, 2017
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Análisis espectroscópico de las películas de CoP que electrocatalizan la reacción de evolución de hidrógeno
Fadl H Saadi, Azhar I Carim, Walter S Drisdell1
1Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
Journal of the American Chemical Society
|August 29, 2017
Resumen
Los fosfuros de metales de transición como el fosfuro de cobalto (CoP) son catalizadores efectivos para la reacción de evolución de hidrógeno (HER) en soluciones ácidas. La espectroscopia operando revela que el catalizador activo de HER es amorfo, con cobalto casi zerovalente y fósforo reducido.
Área de la Ciencia:
- Ciencias de los materiales
- La electroquímica
- Catálisis
Sus antecedentes:
- Los fosfidos de metales de transición demuestran una alta actividad catalítica para la reacción electroquímica de evolución del hidrógeno (HER).
- Estos materiales también exhiben resistencia a la corrosión química en entornos ácidos, lo que los hace adecuados para aplicaciones electroquímicas.
Objetivo del estudio:
- Caracterizar químicamente los catalizadores de cobalto depositado (COP).
- Para comprender el comportamiento del catalizador durante el HER en medios ácidos.
- Elucidar las especies activas responsables de la catálisis en condiciones operando.
Principales métodos:
- Las mediciones de la reacción electroquímica de evolución del hidrógeno (HER) en 0,500 M H2SO4 ((aq).
- Espectroscopía Raman ex situ y in situ/operando.
- Espectroscopia de absorción de rayos X (XAS) ex situ y in situ/operando.
Principales resultados:
- Los análisis ex situ revelaron múltiples fases ordenadas y desordenadas con estados de oxidación mixtos de las especies Co y P.
- La espectroscopia operando indicó que el catalizador activo es principalmente amorfo.
- El electrocatalizador activo se compone predominantemente de especies de cobalto (Co) y fósforo reducido (P) casi zerovalentes.
Conclusiones:
- El fosfuro de cobalto (CoP) exhibe un excelente rendimiento catalítico para el HER en medios ácidos.
- Las especies catalíticas activas bajo condiciones operando difieren del material como preparado, siendo amorfas y ricas en Co y P reducidos.
- Las técnicas espectroscópicas proporcionan información crucial sobre el estado químico de los catalizadores durante las reacciones electroquímicas.
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