Host Metal Deposition on the Supports

Pt and Pd supported on alumina are prepared by a dry impregnation technique using a toluene solution of platinum or palladium acetylacetonate Pt(C5H702)2 and Pd(CsH702)2, following the procedure already described [92]. 

Rh supported on alumina is prepared by impregnation of the support with RhQs in aqueous solution [93]. 

Rh supported on silica is prepared by the cationic exchange technique, using an aqueous solution of chloropentamine rhodium hydroxide RhCl(NH3)5(OH)2, following the procedure already described [93]. 

Ru supported on silica is prepared by grafting of triruthenium dodecacarbonyl RU3CO12 onto the support followed by decomposition in vacuo at 373 K to form metallic ruthenium particles covered by adsorbed CO. Adsorbed CO is then removed at 673 K in vacuo. The procedure was described by TheoUer et al. [95]. Ni/alumina is a commercial catalyst supplied by IFP. Ni supported on silica is prepared by the cationic exchange technique, using an aqueous solution of hex-amine nickel hydroxide Ni(NH3)6(OH)2, following the procedure already described [96]. Ir supported on silica is prepared by decomposition of Ir(Acac)3 absorbed on the silica surface, following the procedure already described [97]. 

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