| 摘要 |
PURPOSE:To make the contribution of catalytic components to nitrogen oxides more effective by forming a nitrogen oxides reducing catalyst by depositing at least one catalytic active component among Cu, Cr, Ni to only the surface region of a carrier. CONSTITUTION:At least one kind of active catalyst component among Cu, Cr, and Ni is deposited to only the surface region of a carrier consisting of alumina, alumina-silica, or zeolite, etc. having pref. >=2.3mm particle size by the electroless plating method to produce thus a nitrogen oxides reducing catalyst. The active catalyst components are deposited pref. to only the surface region within 20mum depth from the surface of the carrier. The catalyst having a constitution as described above causes less decrease of rate of reduction for nitrogen oxides against the increase of SV than conventional catalysts, having also higher efficiency for reducing nitrogen oxides than conventional catalysts. |
