EXHAUST PURIFICATION APPARATUS FOR INTERNAL COMBUSTION ENGINE

摘要

Provided is an exhaust purification apparatus for an internal combustion engine with a DPF comprising a Ce-Ag catalyst disposed in an exhaust system of the internal combustion engine, such that accumulation of ash on the DPF can be suppressed, increases in pressure loss and PM regeneration temperature as well as a decrease in fuel efficiency can be suppressed over a long period, and the ash can be removed efficiently. A surface of the DPF comprising the Ce-Ag catalyst is coated with a solid acid with an acid strength greater than the acid strength of SO3 and smaller than the acid strength of SO4. A control for increasing the temperature of the DPF for an ash regeneration operation includes further increasing the temperature of the DPF following a PM regeneration operation.