Patent ID: 6174835
Filing Date: 2001-01-16
Classification: B01D,B01J,Y02T

Abstract:
An exhaust gas purifying catalyst for use in an oxygen surplus atmosphere, comprising:a brown millerite composite oxide for directly decomposing and absorbing nitrogen oxide (NO.sub.x), anda noble metal-series reducing catalyst disposed on the surface of said brown millerite composite oxide, the brown millerite composite oxide being represented by one of the following formulae:A.sub.3-a B.sub.a C.sub.4-b D.sub.b O.sub.9,A.sub.2-a B.sub.a C.sub.2-b D.sub.b O.sub.5, andA.sub.1-a B.sub.a C.sub.2-b D.sub.b O.sub.4where 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.ltoreq.a<1 and b is within the range 0.ltoreq.b<2.