| 摘要 |
PURPOSE:To make the catalyst performance highly active in an exhaust gas purifying catalyst being formed by depositing noble metal, for example, as an active seed on a metal containing silicate. CONSTITUTION:A catalyst device C provided in an exhaust system has a cracking layer A and a catalyst B for purifying NOx, and the exhaust gas at first is brought into contact with the cracking layer A and HC is transferred to the catalyst B in the state that paraffinic hydrocarbon in the HC is converted into olefin hydrocarbon by a dehydration reaction. Thus the NOx is decomposed into to N2 and O2 in the presence of a highly reactive olefin hydrocarbon and both the HC and NOx are efficiently removed. |
