STUDIES ON PTXINY BIMETALLICS IN NAY .1. PREPARATION AND CHARACTERIZATION

Bimetallic PtxInyNaY samples having a constant platinum loading of 5 wt.% and varying indium content (1 to 5 wt. %) were prepared by ion exchange. The samples were characterized by chemisorption of hydrogen, transmission electron microscopy (TEM), scanning transmission electron microscopy-energy dispersive X-ray (STEM-EDX) analysis, X-ray photoelectron spectroscopy (XPS), and infrared spectroscopy (IR) of adsorbed CO. PtxIny bimetallics have been found in the NaY support as small (8-20 Angstrom) particles as shown by TEM. H-2 and CO chemisorption studies indicated that the number of Pt surface atoms decreases when the indium loading is increased. XPS results indicated that part of the indium is at zero oxidation state, but there is no evidence for a change in the electronic properties of the platinum. (C) 1995 Academic Press, Inc.