The invention described herein involves a novel approach to the production
of oxidation/reduction catalytic systems. The present invention serves to
stabilize the tin oxide reducible metal-oxide coating by co-incorporating
at least another metal-oxide species, such as zirconium. In one
embodiment, a third metal-oxide species is incorporated, selected from
the group consisting of cerium, lanthanum, hafnium, and ruthenium. The
incorporation of the additional metal oxide components serves to
stabilize the active tin-oxide layer in the catalytic process during
high-temperature operation in a reducing environment (e.g., automobile
exhaust). Moreover, the additional metal oxides are active components due
to their oxygen-retention capabilities. Together, these features provide
a mechanism to extend the range of operation of the tin-oxide-based
catalyst system for automotive applications, while maintaining the
existing advantages.