| abstract |
(57) [Abstract] [Objective] When a hydrocarbon or an oxygen-containing organic compound is used as a reducing agent, the nitrogen oxide is reduced as a reducing agent even in the presence of oxygen, and particularly in the presence of oxygen and water. Since it selectively reacts with nitrogen oxides, it can efficiently reduce nitrogen oxides in exhaust gas without using a large amount of reducing agent, and it has excellent durability even in the presence of water. It is to provide a reduction catalyst. A catalyst for catalytic reduction of nitrogen oxides using a hydrocarbon or an oxygen-containing organic compound according to the present invention as a reducing agent comprises a solid acid carrier (a) Ib, IIa, IIb, IIIa and III of the periodic table. b, IVa, IVb, Va, VIa, VIIa, and at least one element selected from Group VIII elements, and (b) cerium oxide is supported, and the total weight of the solid acid carrier and cerium oxide is such that cerium oxide is It is loaded at a loading rate in the range of 5 to 80% by weight, and in the total weight of the solid acid carrier, the (a) group element, and the (b) cerium oxide, the (a) group element is 0.01 to 50%. It is carried at a carrying rate in the range of weight%. |