| 摘要 |
A catalyst able to overcome defects of an absorption reduction-type NOx purifying catalyst, such as poor NOx purifying capability at low temperatures and low SOx desorbing property, is provided. The catalyst is an absorption reduction-type NOx purifying catalyst where NOx absorbent particles and support particles having supported thereon a catalyst component are mixed. Preferably, acidic support particles are added to the support particle, the NOx absorbent particles are a metal oxide having a base point, and the metal oxide is rare earth-added zirconia. In conventional catalysts, the NOx absorbent such as alkali metal having strong basicity exposes the catalyst component present together on the same support to the basic condition to decrease the catalytic performance. However, in the present invention, the NOx absorbent and the support are separate particles, whereby the catalyst component can exert its original catalytic performance and, as a result, the NOx purifying capability at low temperatures and the SOx desorbing property are improved. <IMAGE>
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