Artículo
Kinetics of hydrogen chemisorption on high surface area Pd/Ce 0.8Zr0.2O2
Gennari, Fabiana Cristina
; Neyertz, Claudia A.
; Meyer, Gabriel Omar
; Fornasiero, P.; Graziani, Natalia Soledad
Fecha de publicación:
12/2005
Editorial:
Elsevier Science Sa
Revista:
Journal of Alloys and Compounds
ISSN:
0925-8388
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
The effect of pre-reduction conditions on the H2 chemisorption kinetics of high surface area Pd(0.53 wt.%)/Ce0.8Zr 0.2O2 was investigated by means of temperature-programmed reduction, oxygen-storage capacity, IR spectroscopy and volumetric hydrogen measurements. In the 20-80 ° C range, the pre-reduction rate was very fast and dependent on temperature, with an apparent activation energy of 58 kJ mol-1. Distinction between PdO reduction and H spillover processes is only possible at low H2 pressures. The total H2 uptake and the chemisorption rate strongly decrease by the use of high H2 pressures during the pre-reduction process. Irreversible reduction with the concomitant oxygen vacancies formation occurs at low temperature, as demonstrated by in situ IR experiments. However, H2 uptake on the Pd(0.53 wt.%)/Ce0.8Zr0.2O2 during pre-reduction and chemisorption is recovered by reoxidation at 400 ° C.
Palabras clave:
Ceria Based Materials
,
Chemisorption
,
Hydrogen
,
Metals
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Articulos(INCAPE)
Articulos de INST.DE INVEST.EN CATALISIS Y PETROQUIMICA "ING. JOSE MIGUEL PARERA"
Articulos de INST.DE INVEST.EN CATALISIS Y PETROQUIMICA "ING. JOSE MIGUEL PARERA"
Citación
Gennari, Fabiana Cristina; Neyertz, Claudia A.; Meyer, Gabriel Omar; Fornasiero, P.; Graziani, Natalia Soledad; Kinetics of hydrogen chemisorption on high surface area Pd/Ce 0.8Zr0.2O2; Elsevier Science Sa; Journal of Alloys and Compounds; 404-406; SPEC. ISS.; 12-2005; 317-322
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