EXHAUST EMISSION CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To improve NOx purifying performance by quickening a time for the temperature of a NOx selective reduction catalyst device to be within a temperature window and elongating a time for staying within the temperature window.

SOLUTION: This exhaust emission control device 6 for an internal combustion engine 1 comprises an oxidation catalyst device 8 and the NOx selective reduction catalyst device 9 arranged right on the downstream side of the oxidation catalyst device 8. The temperature rise property of the wall of a cell formed on a carrier for the oxidation catalyst device 8 is superior to that of the wall of a cell formed on a carrier for the NOx selective reduction catalyst device 9, and the wall thickness thereof is less than that of the wall of the NOx selective reduction catalyst device 9. The heat storage property of the wall of the NOx selective reduction catalyst device 9 is superior to that of the wall of the oxidation catalyst device 8.

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