PALLADIUM SILICIDE FORMATION FROM SILICA-SUPPORTED PALLADIUM CATALYSTS

10 Wt% metal-loaded Pd/SiO2 catalysts were reduced at temperatures fro m 380-degrees-C to 600-degrees-C and investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and neopentane conversi on as a catalytic probe. The X-ray diffraction study showed the presen ce of the Pd3Si orthorhombic phase in a highly reduced Pd/SiO2 sample. The extent of the Pd-SiO2 interaction positively correlates with the metal dispersion. An increase in the selectivity for isomerization in neopentane conversion appears to be a good measure of metal-supported interactions.