CATALYST CATALYTIC REDUCTION OF FOR NITROGEN OXIDE

摘要

PURPOSE:To perform the catalytic reduction of a nitrogen oxide efficiently in exhaust gas under the coexistence of oxygen by carrying a perovskite type composite oxide of specified structure as a catalyst for nitrogen oxide catalytic reduction in which hydrocarbon and/or oxygen containing compound is sued as a reducing agent on a solid carrier. CONSTITUTION:A perovskite composite oxide represented by the formula I (A is an element such as Y or La, B is an element such as Ba or Sr and C is an element such as Mn or Co. 0<=X<=1) is used. Said perovskite type composite oxide is carried on a carrier of solid acid of zeolite group or the like composed of alkali metal in zeolite ion exchanged by ammonium ion or hydrogen ion. In the case hydrocarbon containing a compound is used as a reducing agent, the hydrogen oxide is reacted selectively with hydrocarbon and the oxygen containing compound under the coexistence of oxygen in said catalyst, and the nitrogen oxide can be reduced efficiently without using a large amount of reducing agent.