INFLUENCE OF METALLIC PRECURSORS ON THE PREPARATION OF SILICA-SUPPORTED PTSN ALLOY - CHARACTERIZATION AND REACTIVITY IN THE CATALYTIC ACTIVATION OF CO2

The preparation of a single, well-defined PtSn phase supported on silica was carried out by the definitive interaction of cis-[PtCl2(PPh(3))(2)] and SnCl2 with the hydroxyl surface groups of silica. After a reduction step, the only metallic phase present on the catalyst was the supported PtSn alloy, which was unambiguously characterized by X-ray diffraction, transmission electron microscopy, energy dispersive X-ray analysis, electron nanodiffraction, and X-ray photoelectron spectroscopy. Its structural properties and improved catalytic behaviour in the CO2 reaction with C2H4 and H-2 or H2O are contrasted with those of a conventional catalyst prepared from H2PtCl6 and SnCl2. (C) 1995 Academic Press, Inc.