EXHAUST PURIFICATION DEVICE OF INTERNAL COMBUSTION ENGINE

摘要

In an internal combustion engine, an NOx selective reduction catalyst (15) is arranged in the engine exhaust passage, and the amount of deposition of the HC deposited at the NOx selective reduction catalyst (15) is estimated. When the estimated HC deposition amount exceeds a predetermined allowable deposition amount, the NOx selective reduction catalyst (15) is raised in temperature to make the deposited HC desorb from the NOx selective reduction catalyst (15), and thereby the NOx selective reduction catalyst (15) from HC poisoning is restored.