CATALYST FOR EXHAUST GAS PURIFICATION

摘要

A catalyst for exhaust gas purification which can retain the catalytic activity of platinum on a high level over long and can realize excellent exhaust gas purification performance. The catalyst is prepared so as to contain a composite oxide of the perovskite structure represented by the general formula (1): A1-xA'xB1-y-zB'yPtzO3 (1) wherein A represents at least one element selected among rare earth elements certainly including one or more rare earth elements having a valance of 3 as the only valence; A' represents at least one element selected among the alkaline earth metals and silver; B represents at least one element selected among iron, manganese, and aluminum; B' represents at least one element selected among the transition elements excluding platinum, iron, manganese, cobalt, and the rare earth elements; and x, y, and z, which indicate the proportions of atoms, are numbers satisfying 0 < x <= 0.5, 0 <= y < 0.5, and 0 < z <= 0.5.