Patent ID: 7344684

Claim:
An exhaust emission purifying catalyst device, comprising: a single carrier that is disposed in an exhaust passage and includes a large number of through holes extending through said single carrier in a flowing direction of exhaust gasses; and supporting layers made of fire-resistant inorganic oxide and formed on inner surfaces defining the through holes; wherein said supporting layers support noble metal and NOx trapping agents for occluding NOx in exhaust gas when an exhaust air-fuel ratio is lean, and the exhaust emission purifying catalyst device emits and reduces the occluded NOx when an exhaust air-fuel ratio is stoichiometric or rich, and the amount of the noble metal supported on said supporting layers is set to be smaller in an exhaust passage upstream area of said carrier than in an exhaust passage downstream area of said carrier, and wherein the supporting layers are composed mainly of potassium in the exhaust passage upstream area and are composed mainly of barium in the exhaust passage downstream area.