| 摘要 |
PROBLEM TO BE SOLVED: To provide a contact reduction method of nitrogen oxides by using hydrocarbons as a reducing agent, namely, to provide a contact reduction method of nitrogen oxides by which nitrogen oxides in an exhaust gas can be stably and efficiently reduced by a contact method at low temp. without using a large amt. of a reducing agent. SOLUTION: In a contact reduction method of nitrogen oxides included in an exhaust gas by using a reducing agent in the presence of a catalyst, an exhaust gas containing nitrogen oxides and a reducing agent comprising hydrocarbons is brought into contact with a first catalyst in the first stage. This catalyst is provided by depositing chlorine ion by 0.05 to 2wt.% on an alumina. Then, in the second stage, the exhaust gas is brought into contact with a second catalyst selected from silver, silver oxide and silver aluminate. |
