| 摘要 |
PURPOSE: To bring nitrogen oxide not only in an exhaust gas from Diesel engine, of cause gasoline engine, but in an exhaust gas generated from various equipments into contact with a specific catalyst in the presence of a small quantity of hydrocarbons added or hydrocarbons contained in the exhaust gas in an oxidizing atmosphere as a whole, in which excess oxygen exists. CONSTITUTION: The exhaust gas containing nitrogen oxide is brought into contact with the catalyst having at least one kind of a metal selected from a group composed of yttrium, magnesium, zinc, lanthanum carried on silica in the oxidizing atmosphere in which excess oxygen exists and in the presence of hydrocarbons. The catalyst preferably contains 0.01-10wt.% cobalt based on the catalyst as a reference and expressed in terms of oxide. |
