摘要 |
A complex oxide that exhibits high redox ability even at low temperatures, has excellent heat resistance, and stably retains these characteristics even on repeated oxidation and reduction at high temperature; a method for producing the same; and an exhaust gas purification catalyst. The inventive complex oxide contains Ce; rare earth metal element other than Ce, including Y; Al and/or Zr; and Si; such that the Ce, and said other elements other than Ce and Si, are present in a mass ratio of 85:15-99:1, calculated as oxides; and has a characteristic such that when it is subjected to temperature-programmed reduction (TPR) measurement in a 10% hydrogen-90% argon atmosphere at from 50°C to 900°C with the temperature increasing at a rate of 10°C/min, followed by oxidation treatment at 500°C for 0.5 hours, and then temperature-programmed reduction measurement is performed again, its calculated reduction rate at and below 400°C is at least 2.0%. |