POLYFUNCTIONAL CATALYSTS AND METHODS OF USE

This invention provides polyfunctional catalysts comprising a composite of platinum and one or more of rhodium, ruthenium and iridium, a substantially larger quantity of one or more base metal oxides in which the metal is selected from the group consisting of metals having an atomic number from 25 to 28 and rhenium, and an alumina support, which composite is made and then deposited on a suitable carrier. In a preferred embodiment, the catalysts contain 1-20 weight percent of said base metal oxide, typically nickel oxide; 0.05-0.5 weight percent platinum; and 0.002-0.3 weight percent rhodium, and an alumina support deposited on a monolith or other carrier. The improved catalysts are especially applicable for purifying exhaust gases from combustion processes, and in particular those from internal combustion engines.