CATALYST FOR PURIFYING EXHAUST GAS FROM INTERNAL COMBUSTION ENGINE AND PURIFYING METHOD THEREOF

摘要

The present invention is directed to a catalyst being formed of a porous supporter supporting alkali metals, Ti and noble metal, or further supporting at least one of a rare earth metal and magnesium, being disposed in a flow passage of an internal combustion engine, and being used to purify NOx contained in the exhaust gas. The catalyst of the present invention has excellent NOx resistance not only to the exhaust gas burnt with a stoichiometric air-to-fuel ratio or rich conditions, but to the exhaust gas burnt with the lean conditions, and furthermore has a high resistivity to poisoning of SOx slightly contained in the fuel.