CATALYST FOR PURIFYING EXHAUST GAS AND METHOD THEREFOR

摘要

PURPOSE:To more improve NOx removal performance after a durability test in a method for purifying exhaust gas by simultaneously removing CO, hydrocar bon and NOx in the exhaust gas in an atmosphere contg. excess oxygen. CONSTITUTION:Exhaust gas contg. excess oxygen is brought into contact with a catalyst for purification of exhaust gas obtd. by carrying at least one of Pt and Pd and at least one kind of metal selected among alkali metals, alkaline earth metals and rare earth metals on an alumina carrier contg. Li allowed to enter into solid soln. Since it is considered that a multiple sulfate formed by SO2 in exhaust gas is decomposed by lithium at a low temp. in a reducing atmosphere, the acidification of the alumina is prevented and the NOx adsorbing ability of the alkali metals, etc., is kept high. The NOx removal performance of the catalyst after a durability test can be therefore improved.