| 摘要 |
PURPOSE:To provide an exhaust gas purifying catalyst which has improved NOx removing capacity in a lean atmosphere and can remove NOx in exhaust gas in a wide temperature range from a low to high temperatures and a method for making the catalyst. CONSTITUTION:The catalyst is made from a multi-component complex oxide containing copper, nickel, zinc, and aluminum which is expressed by a general formula of CuaNibZncAldOg (a, b, c, and d indicate the atomic ratio of elements, a=0.01-0.3, b=0.2-0.8, c=0.01-0.5 when d=2.0, and g is the number of oxygen atoms necessary to satisfy the atomic valencies of the above components.) At least one kind of an aqueous solution of a compound selected from the group consisting of ammonia, ammonium carbonate, ammonium hydrogen carbonate, ammonium sulfate, etc., is incorporated into an aqueous solution or an aqueous dispersion liquid containing the metal compounds constituting the complex oxide, after the pH of the solution being adjusted at 7.0-9.0, water is removed, and the residue is heat-treated. |
