PREPARATION AND CHARACTERIZATION OF SUPPORTED MONONUCLEAR METAL-COMPLEXES AS MODEL CATALYSTS

Metal acetylacetonates (M(n+) = Cu, Pt, Pd, Fe, Cr, Co, and Mn) were supported on Cab-O-Sil by batch impregnation. All samples were analyzed for metal, hydrogen, and carbon content. The C/M(n+) stoichiometry and metal content of the supported catalysts depended upon the metal acetylacetonate. High metal contents were observed in those supported samples for which M(n+) = Cu, Mn, and Co, whereas the other samples showed only small amounts of metal ion. Moreover, the C/M(n+) stoichiometry of the supported complexes containing Cu and Cr were the same as the parent acetylacetonates, whereas the C/M(n+) stoichiometry was lower than that of the metal acetylacetonates for M(n+) = Co, Mn, and Fe. The samples containing Cu were characterized by diffuse reflectance, Fourier transform infrared spectroscopy (DRIFTS) to determine the structure of the surface species. Subsequently, the copper samples were decomposed in air by heating in a thermal gravimetric apparatus (TGA) to 400-degrees-C. The kinetics of the weight changes depended upon the loading of the Cu complexes in the sample.