INIFTA   05425
INSTITUTO DE INVESTIGACIONES FISICO-QUIMICAS TEORICAS Y APLICADAS
Unidad Ejecutora - UE
artículos
Título:
Lowering the synthesis temperature of Ni2P/SiO2 by palladium addition
Autor/es:
VICTOR TEIXEIRA DA SILVA; L.A. SOUSA; R.M. AMORIM; LEANDRO ANDRINI; SANTIAGO J. A. FIGUEROA; F.G. REQUEJO; F.C. VICENTINI
Revista:
JOURNAL OF CATALYSIS
Editorial:
ACADEMIC PRESS INC ELSEVIER SCIENCE
Referencias:
Año: 2011 vol. 279 p. 88 - 102
ISSN:
0021-9517
Resumen:
The addition of small amounts of palladium (0.1%, 0.5% and 1.0% w/w) to a NixPyOz/SiO2 sample led to a decrease of 200 K in the synthesis temperature of Ni2P/SiO2, allowing synthesis to proceed at 723 K. In situ X-ray diffraction (XRD) and X-ray absorption near-edge structure (XANES) experiments demonstrated that the phosphate ?phosphide transformation started at approximately 673 K, and the total time to reduce the phosphate phase was decreased by the presence of palladium. Based on the in situ P K-edge XANES experiments and CO chemisorption uptakes, it was proposed that, depending on the amount of palladium incorporated, the final catalysts present different degrees of reduction, thereby impacting catalytic activity. An increase in activity was observed for the palladium-containing samples during time on stream, which might be associated with the formation of a phosphosulfide active species. The extent of the phosphosulfide species formation was dependent on the degree of reduction.