EXHAUST PURIFIER OF INTERNAL COMBUSTION ENGINE AND METHOD OF EXHAUST PURIFICATION

摘要

SO_X trap catalyst (11) having at least either an alkali metal or an alkaline earth metal dispersed and supported therein is disposed in an exhaust passage of internal combustion engine. During engine drive, the temperature of the SO_X trap catalyst (11) is maintained at one at which a nitrate of at least either an alkali metal or an alkaline earth metal becomes a molten form to thereby promote the action of nitrate migration coagulation inducing the migration to the surface of the SO_X trap catalyst (11) and coagulation of the nitrate within the SO_X trap catalyst (11). By virtue of this action of nitrate migration coagulation, SO_X is removed while attaining recovery of SO_X trap ratio.