| 摘要 |
<P>PROBLEM TO BE SOLVED: To form an adsorbent layer which prevents a cracking in the circumference direction and in the radial direction independently of the SAR (systemic acquired resistance) of a zeolite and to suppress peeling of the adsorption layer and chipping of the whole of a coating layer even after a long life of heat history. <P>SOLUTION: The exhaust gas purifying catalyst is obtained by stacking on a carrier an HC (hydrocarbons) adsorbent layer having no crack and comprising a zeolite and a silica sol binder represented by the formula Y=a(X)<SP>2</SP>+b(X)+c and a catalyst component layer comprising noble metals such as platinum, palladium and rhodium, and alumina, ceria and zirconia. The catalyst is manufactured as follows; a slurry containing a β-zeolite having a silica to alumina ratio of 10-100 and a silica sol is mixed with a silica sol binder, 10-90% of which is represented by the above formula, the resulting mixture is applied to a monolithic carrier and dried/fired to form the HC adsorbent layer, and the catalyst component layer is formed on the HC adsorbent layer. <P>COPYRIGHT: (C)2004,JPO |
