EXHAUST PURIFIER OF INTERNAL COMBUSTION ENGINE AND METHOD OF EXHAUST PURIFICATION

摘要

An SO X trap catalyst (11) in which at least one of an alkali metal and alkali earth metal is carried diffused is arranged in an exhaust passage of an internal combustion engine. By holding the temperature of the SO X trap catalyst (11) during engine operation at the temperature where a nitrate of the at least one of the alkali metal and alkali earth metal becomes the melted state, a nitrate movement and coagulation action where the nitrate in the SO X trap catalyst (11) moves to and coagulates at the surface of the SO X trap catalyst (11) is promoted. Due to this nitrate movement and coagulation action, SO X is removed while restoring the SO X trap rate.