MOCVD OF RHODIUM, PALLADIUM AND PLATINUM COMPLEXES ON FLUIDIZED DIVIDED SUBSTRATES - NOVEL PROCESS FOR ONE-STEP PREPARATION OF NOBLE-METAL CATALYSTS

A new one-step method, entitled fluidized-bed metal-organic chemical v apor deposition (FBMOCVD) of preparing highly dispersed metal-supporte d catalysts is reported, The following complexes were studied and used as CVD precursors in presence of H-2: [Rh(mu-Cl)(CO)(2)](2), Rh(allyl )(3), Rh(acac) (CO)(2), Pd(allyl)(hfac), Pd(allyl)(Cp), Pt(COD)(CH3)(2 ), (acac, acetylacetonato; hfac, hexafluoroacetylacetonato; Cp, cyclop entadienyl; GOD, cyclooctadienyl). In a first approach, depositions on planar substrates were carried out to establish the best experimental conditions to obtain good-quality deposits, X-ray diffraction, X-ray photo-electron spectroscopy and electron microprobe studies were reali zed on the resulting thin films, Analyses of the products contained in the gas phase after and during deposition were performed by mass spec trometry and GC-MS, Finally, catalysts prepared by FBMOCVD were charac terized by transmission electron microscopy-energy dispersion spectros copy (TEM-EDS), metal-loading determinations and specific-surface meas urements (BET), Dispersed nanosized aggregates were obtained, showing high activities in alkene hydrogenation and alcohol hydrocarbonylation . (C) 1998 John Wiley & Sons, Ltd.