| 摘要 |
PROBLEM TO BE SOLVED: To produce an exhaust gas cleaning catalyst excellent in low temperature ignitability, developing catalytic activity at a lower temperature as compared with a catalyst system used heretofore. SOLUTION: This exhaust gas cleaning catalyst contains catalytically active components containing at least one noble metal component selected from palladium, platinum and rhodium, a refractory inorganic oxide and zirconium oxide containing both cerium and an Additive. The additive is an oxide of at least one element selected from the group consisting of Y, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, Sn and In. The crystal of zirconium oxide containing cerium and the additive is a single structure of tetragonal zirconium oxide. |
