| 摘要 |
PURPOSE:To efficiently reduce nitrogen oxides in exhaust gas by a catalyst obtained by supporting perovskite type composite oxide represented by a specific general formula on a solid acid carrier. CONSTITUTION:A catalyst for catalytically reducing nitrogen oxides using hydrocarborns and/or an oxygen-containing compound as a reducing agent is constituted by supporting perovskite type composite oxide represented by formula (wherein A is at least one kind of an element selected from La, Y, Ce or the like, B is at least one kind of an element selected from Ba, Sr, Ca or the like, C is at least one kind of an element selected from Mn, Co, Fe or the like and (x) is O<=X<=1) on a solid acid carrier. By this catalyst, nitrogen oxide is selectively reacted with hydrocarbon or an oxygen-containing compound in the coexistence of oxygen and nitrogen oxides in exhaust gas is efficiently reduced without using a large amount of a reducing agent. |
