NOX OCCLUSION REDUCTION TYPE CATALYST

摘要

PROBLEM TO BE SOLVED: To suppress the lowering of a NOx occlusion capacity caused by the increase of temperature by suppressing the temperature increase of a catalyst layer after rich spike.

SOLUTION: A temperature controlling material whose specific heat is higher than that of carrier powder is incorporated into a coat layer. The temperature change of the coat layer itself is controlled, and even when the temperature of a minute part in a catalyst during rich spike is increased in a short time, the heat is absorbed by the temperature controlling material to suppress the temperature increase of the whole catalyst. Therefore, the lowering of the NOx occlusion capacity by the increase of temperature in the following lean atmosphere is suppressed so that a high NOx occlusion capacity is developed.

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