| 摘要 |
PURPOSE:To prepare a catalyst purifying with high efficiency NOx on the lean side at the high temperature by using a specific composite oxide in which monovalent and bivalent coppers are mixed. CONSTITUTION:A composite oxide of composition represented by (LnxA1-x) (CuyB1-y) O3 (Ln = one selected from La, Ce, Pr and Nd, A = one selected from Sr and/or Ba, B = one selected from Zr, Hf, Nb and Ta, and x=0-1, y=0.33-1.) is used as an exhaust gas purifying catalyst for an automobile. As the catalyst thus prepared is composed of a composite oxide in which monovalent and bivalent coppers may be mixed, reduction reaction of NOx can easily be effected on the lean side at the high temperature excessive oxygen atmosphere, and superior purification performance for NOx is exhibited. |
