English   español  
Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/148402
COMPARTIR / IMPACTO:
Estadísticas
logo share SHARE logo core CORE   Add this article to your Mendeley library MendeleyBASE

Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL
Exportar a otros formatos:
Título

The role of cobalt hydroxide in deactivation of thin film Co-based catalysts for sodium borohydride hydrolysis

AutorPaladini, M. ; Arzac, G.M. ; Godinho, V. ; Hufschmidt, D. ; Jiménez de Haro, M.C.; Beltrán, Ana M.; Fernández-Camacho, A.
Palabras claveHydrogen
Sodium borohydride
Co thin film catalyst
Deactivation
Cobalt hydroxide/oxyhydroxide
Fecha de publicación2017
EditorElsevier
CitaciónApplied Catalysis B - Environmental, 210: 342-351 (2017)
ResumenDeactivation of a Co catalyst prepared as thin film by magnetron sputtering was studied for the sodium borohydride (SB) hydrolysis reaction under different conditions. Under high SB concentration in single run experiments, the formation of a B-O passivating layer was observed after 1.5 and 24 h use. This layer was not responsible for the catalyst deactivation. Instead, a peeling-off mechanism produced the loss of cobalt. This peeling-off mechanism was further studied in cycling experiments (14 cycles) under low SB concentrations. Ex-situ study of catalyst surface after use and solid reaction products (precipitates) was performed by X-Ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM). The presence of cobalt hydroxide and oxyhydroxide was detected as major components on the catalyst surface after use and as precipitates in the supernatant solutions after washing. Cobalt borate, cobalt carbonate and oxycarbonate were also formed but in lesser amounts. These oxidized cobalt species were formed and further detached from the catalyst at the end of the reaction and/or during catalyst washing by decomposition of the unstable in-situ formed cobalt boride. Leaching of cobalt soluble species was negligible. Thin film mechanical detachment was also found but in a smaller extent. To study the influence of catalyst composition on deactivation processes, cycling experiments were performed with Co-B and Co-C catalysts, also prepared as thin films. We found that the deactivation mechanism proposed by us for the pure Co catalyst also occurred for a different pure Co (prepared at higher pressure) and the Co-B and Co-C samples in our experimental conditions
Versión del editorhttp://doi.org/10.1016/j.apcatb.2017.04.005
URIhttp://hdl.handle.net/10261/148402
DOI10.1016/j.apcatb.2017.04.005
Aparece en las colecciones: (ICMS) Artículos
Ficheros en este ítem:
Fichero Descripción Tamaño Formato  
The role of cobalt hydroxide post print version.pdf Embargado hasta 1 de abril de 20192,39 MBAdobe PDFVista previa
Visualizar/Abrir     Petición de una copia
Mostrar el registro completo
 


NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.