Exhaust purification system of 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 NOX 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, NOX released from the silver-alumina-based catalyst device is reduced by reducing material to be purified in the NOX reducing catalyst device. When the temperature of the silver-alumina-based catalyst device becomes a second set temperature on the low temperature side, NOX released from the silver-alumina-based catalyst device is reduced by reducing material to be purified in the NOX reducing catalyst device.