EXHAUST EMISSION CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To provide an exhaust emission control device for an internal combustion engine capable of efficiently using ozone when ozone is supplied to exhaust gas.

SOLUTION: An NOx storage reduction type catalyst 22 is arranged in an exhaust gas passage 12 of the internal combustion engine 10. An NOx oxidation gas supply device 30 supplying air or ozone (O3) to mix the same with exhaust gas flowing into the NOx storage reduction catalyst 22 is provided. Ozone is supplied under conditions where temperature of the NOx storage reduction type catalyst 22 is lower than temperature at which NOx storage acceleration effect due to air supply is developed, and oxygen supply is stopped and air is supplied under a condition where temperature of the NOx storage reduction type catalyst 22 is temperature at which NOx storage acceleration effect due to air supply is developed or higher.

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