6533b82cfe1ef96bd128f6ca

RESEARCH PRODUCT

Relationship between structure and CO oxidation activity of ceria supported gold catalysts

Giuseppe PantaleoM. P. CasalettoA. M. VeneziaF. Leonarda LiottaGiulio DeganelloAlessandro LongoGabriella Di Carlo

subject

Cerium oxideCoprecipitationChemistryInorganic chemistryIonic bondingSurfaces Coatings and FilmsCatalysisMetalX-ray photoelectron spectroscopyvisual_artMaterials Chemistryvisual_art.visual_art_mediumPhysical and Theoretical ChemistryTemperature-programmed reductionDispersion (chemistry)

description

Gold catalysts supported on cerium oxide were prepared by solvated metal atom dispersion (SMAD), by deposition-precipitation (DP), and by coprecipitation (CP) methods and were characterized by X-ray diffraction (XRD), temperature programmed reduction (TPR), and X-ray photoelectron spectroscopy (XPS). The catalytic activity was tested in the CO oxidation reaction. The structural and surface analyses evidenced the presence of a modified ceria phase in the case of the DP sample and the presence of pure ceria and gold metal crystallites in the case of the SMAD and CP samples. The DP sample, after a mild treatment in air at 393 K, exhibited only ionic gold, and it was very active below 273 K. By comparing the activities of the different catalysts, it is suggested that the presence of small gold particles, as obtained by the SMAD technique, is not the main requisite for the achievement of the highest CO conversion. The strong interaction between ionic gold and ceria, by enhancing the ceria surface oxygen reducibility, may determine the particularly high activity.

yearjournalcountryeditionlanguage
2005-01-01
http://www.cnr.it/prodotto/i/175124