EXHAUST PURIFICATION DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

In an exhaust purification system of an internal combustion engine of the present invention, a silver-alumina-based catalyst device and NO x reducing catalyst device are arranged in the engine exhaust system. When a temperature of the silver-alumina-based catalyst device becomes a first set temperature T1 on the high temperature side (step 110), NO x released from the silver-alumina-based catalyst device is reduced by reducing material to be purified in the NO x reducing catalyst device (step 115). When the temperature of the silver-alumina-based catalyst device becomes a second set temperature on the low temperature side (step 104), NO x released from the silver-alumina-based catalyst device is reduced by reducing material to be purified in the NO x reducing catalyst device (step 107).