Structure and Size of Bimetallic Palladium-Platinum Clusters in an Hydrotreatment

D. Bazin (1) , D. Guillaume (2) , Ch. Pichon (2) , D. Uzio (2) , S. Lopez (2)

1 LPS - Laboratoire de Physique des Solides
2 IFPEN - IFP Energies nouvelles

Highly dispersed supported bimetallic PdPt catalysts were prepared by incipient wetness co-impregnation of alumina with platinum bis-acetylacetonate Pt(Acac)2 and palladium bis-acetylacetonate Pd(Acac)2. The resulting Pt4Pd/Al2O3 and Pt6Pd/Al2O3 catalytic systems dedicated to hydro-dearomatization in presence of sulfur were characterized by X-ray absorption spectroscopy, transmission electron microscopy and volumetric H2-O2 titration. Direct structural evidence is given of the presence of nanometer bimetallic particles. Moreover, the complete set of results indicates a "cherry-like" structure for the bimetallic clusters with a preferential distribution of palladium atoms at the cluster surface. Catalytic results shows that the optimum composition leading to the appropriate surface structure must be adjusted as a function of the size of the clusters.

Domaines: Physique [physics]

D. Bazin, D. Guillaume, Ch. Pichon, D. Uzio, S. Lopez. Structure and Size of Bimetallic Palladium-Platinum Clusters in an Hydrotreatment. Oil & Gas Science and Technology - Revue d'IFP Energies nouvelles, 2005, 60 (5), pp.801-813. ⟨10.2516/ogst:2005057⟩. ⟨hal-02044024⟩