Process for treatment of exhaust gases

Claim 1

In a process for treatment of exhaust gases from an internal combustion engine, the steps of: burning a hydrocarbon fuel or a fuel containing hydrocarbons and alcohol blends in the internal combustion engine thereby to generate exhaust gases from the internal combustion engine containing various amounts of unburned hydrocarbons, carbon monoxide, and oxides of nitrogen depending upon operating conditions of the internal combustion engine; and passing said generated exhaust gases over an improved catalyst system, characterized by; a support medium for supporting a catalyst system, said support medium having both an upstream support portion over which exhaust gases initially flow and a downstream support portion over which exhaust gases flow after passing over said upstream support portion thereof; finely divided palladium dispersed by itself on said upstream support portion of said support medium, said palladium being present in an amount of from about 10 to 40 grams per cubic foot of said upstream support portion of said support medium; said downstream support portion of said support medium having a platinum/rhodium three-way catalyst thereon, said platinum to rhodium ratio being from about 11:1 to about 5:1 with said three-way catalyst material being present in an amount of from about 10 to 40 grams per cubic foot of said downstream support portion of said support medium.