| 摘要 |
PURPOSE:To improve the reducing reaction of nitrogen oxide at low temp. of 200 deg.C or less, by forming a low temp. nitrogen oxide reducing catalyst from an amorphous metal powder comprising a specific chemical composition and having a specific surface area of 1m<2>/g or more. CONSTITUTION:A low temp. nitrogen oxide reducing catalyst is formed of an amorphous metal powder having a componential composition represented by formula (wherein Nia shows that Ni is a-atomic % and Xb shows that one of an element or two or more of elements selected from a group consisting of Y, Ti, Zr, Hf, Nb and La is b-atomic %, a is 35-70 and b is 30-65) and a specific surface area of 1m<2>/g or more. This catalyst shows extremely high catalytic activity at 200 deg.C or less and is not lowered in its activity even if used at 200 deg.C or less for a long time. This catalyst has similar high catalytic activity in reducing reaction of not only NO but also other NOX. |
