SEGMENTED THREE-WAY CATALYST

摘要

SEGMENTED THREE-WAY CATALYST A three-way catalyst converter is disclosed for simultaneously treating carbon monoxide ¢CO!, unburned hydrocarbons ¢HC! and oxides of nitrogen ¢NO! found in an exhaust gas stream from an internal combustion engine. The converter includes a converter housing having a catalyst substrate therein. A catalyst selected from the group consisting of rhodium and iridum is deposited only on an initial portion of the catalyst substrate. A catalyst selected from the group consisting of platinum and palladium is deposited on only a latter portion of the substrate. The rhodium and iridum are effected under stoichiometric or slight oxidizing conditions to effect a reduction of NO and an oxidation of some or all the CO. The platinum and palladium are effective under these conditions to oxidize HC and any CO which was not oxidized on the rhodium and iridum.