| 摘要 |
PURPOSE:To efficiently remove nitrogen oxides even in excess oxygen by allowing the exhaust gas containing nitrogen oxides to contact with the catalyst containing Cu, Al and an element selected from among elements of group VIII in periodic table and Ti, etc., as catalyst components in the presence of CO and/or a hydrocarbon selected from among hydrocarbons having specified carbon number. CONSTITUTION:The exhaust gas containing nitrogen oxides is allowed to contact with the catalyst containing Cu, Al and at least one kind element selected from among elements of group VIII in periodic table, Ti, Cu, V, Mn, Zn, Ga, Zr, Nb, Ag, W and Au as catalyst components in the presence of CO and/or >=1 kind hydrocarbon selected from among 1-24C hydrocarbons to remove the nitrogen oxides. In such a way, the catalyst which is capable of purifying efficiently the nitrogen oxides in the exhaust gas even in excess oxygen, excellent in water resistance and heat resistance, etc., as compared with a conventional copper-containing zeolites catalyst and can be used not only for a lean-burn and for a diesel engine but also for the replacement of a current by used ternary catalyst. |
