Bimetallic PtxInyNaY samples having a constant platinum loading of 5 w
t.% and varying indium content (1 to 5 wt. %) were prepared by ion exc
hange. The samples were characterized by chemisorption of hydrogen, tr
ansmission electron microscopy (TEM), scanning transmission electron m
icroscopy-energy dispersive X-ray (STEM-EDX) analysis, X-ray photoelec
tron 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 indi
um 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, In
c.