Catalytic studies on the mixed ceria-zirconia doped La~(3+)、Pr~(3+) or Mn~(4+)

摘要

A number of experiments were carried out with different Ce-Zr oxides doped La~(3+)、Pr~(3+) or Mn~(4+) in order to improve their performance as a promoter for three way catalyst(TWC). The XRD results showed that the thermal stability of Ce-Zr oxide doped lanthanum or praseodymium was improved, especially at high temperature. H_2-TPR test detected the low -temperature redox behavior of Ce-Zr oxide was promoted strongly attributed to the MnO_2, with calcined temperature increasing, the reduction peaks were moved to high temperature for Ce-Zr oxide doped La~(3+) and Pr~(3+). The catalytic activity of Ce-Zr oxide doped Mn~(4+) was also enhanced, the light-off temperature was lower 1 OK than Ce-Zr oxide; the conversions of CO and THC were higher 3-4% than Ce-Zr oxide.