Metal oxide catalytic compositions having perovskite crystal structures and containing metals of the platinum group

Abstract

Metal oxides of the type [A.sup.1.sub.1-x A.sup.2.sub.x ]B'.sub.1-y Me.sub.y ]O.sub.3 having perovskite-type crystal structures in which A.sup.1 and A.sup.2 are each one or more mono-, di-, or trivalent metals having ionic radii between about 0.8 and 1.65 Angstroms; B' is one or more metals having ionic radii between about 0.4 and 1.4 Angstroms; Me is one or more metals of the platinum group (ruthenium, osmium, rhodium, iridium, palladium, and platinum); x is between about 0.01 and 0.99; and y is between about 0.01 and 0.20 Are useful as catalysts for the oxidation of hydrocarbons and carbon monoxide and for the reduction of nitrogen oxides under conditions typical of those involved in the cleanup of the exhaust gases of internal combustion engines.

Dependencies are inferred from the claim text.