| abstract |
An exhaust gas purifying catalyst for use in an oxygen surplus atmosphere, includes a brown millerite composite oxide for directly decomposing and absorbing nitrogen oxide (NO x ), and a noble metal-series reducing catalyst disposed on the surface of said brown millerite composite oxide. The brown millerite composite oxide is represented by one of the following formulae: n n n A 3-a B a C 4-b D b O 9 , n n n n n A 2-a B a C 2-b D b O 5 , and n n n n n A 1-a B a C 2-b D b O 4 n n n where A and B are elements selected from the group consisting of Ba, Ca, Sr, Mg and Ce, C and D are elements selected from the group consisting of Y, Dy, Zn, Ti, Mn, Fe, Co, Ni, Cu, Sn, Zr and Nd, a is within the range 0≦a<1, and b is within the range 0≦b<2. |