초록 ▼

A composite catalyst includes a first catalyst part containing an Ir catalyst and a second catalyst part covering the first catalyst part and containing a perovskite type composite oxide. The perovskite type composite oxide contributes mainly to oxidation reaction such as NO+O.sub.2.fwdarw.NO.sub.2

A composite catalyst includes a first catalyst part containing an Ir catalyst and a second catalyst part covering the first catalyst part and containing a perovskite type composite oxide. The perovskite type composite oxide contributes mainly to oxidation reaction such as NO+O.sub.2.fwdarw.NO.sub.2 in an atmosphere of excess oxygen while the Ir catalyst contributes mainly to reduction reaction with HC (hydrocarbon) as a reducing agent such as NO.sub.2 +HC+O.sub.2.fwdarw.N.sub.2 +CO.sub.2 +H.sub.2 O.

대표청구항 ▼

[ What is claimed is:] [1.]1. A composite catalyst for purification of exhaust gas comprising:a first catalyst part containing an Ir catalyst; anda second catalyst part covering said first catalyst part and comprising a perovskite type composite oxide, wherein said perovskite type composite oxide co

[ What is claimed is:] [1.]1. A composite catalyst for purification of exhaust gas comprising:a first catalyst part containing an Ir catalyst; anda second catalyst part covering said first catalyst part and comprising a perovskite type composite oxide, wherein said perovskite type composite oxide comprises LaCoO.sub.3.