| 摘要 |
PURPOSE: To efficiently purify the exhaust gas of a diesel engine without adding a reducing agent such as ammonia by bringing a laminar tin phosphate compd. having silica interposed between the layers thereof as pillars or a laminar tin phosphate compd. further containing one or more kinds of transition metals into contact with exhaust gas. CONSTITUTION: This exhaust gas purifying catalyst is a laminar tin phosphate compd. having silica, alumina or zirconia interposed between the layers thereof as pillars and produced, for example by mixing crystalline tin phosphate with a silane coupling agent to subject the resultant mixture to heat treatment and baking treatment in succession. Further, one or more kinds of transition metals such as Cu and Co can be added to the laminar tin phosphate compd. being the exhaust gas purifying catalyst. By bringing the exhaust gas purifying catalyst thus prepared into contact with an oxygen excessive exhaust gas containing nitrogen oxides and hydrocarbons, for example, an exhaust gas high in air/fuel ratio, nitrogen oxides can be efficiently removed from the exhaust gas. |
