MO x and Au/MO x catalysts were prepared by the coprecipitation method and their catalytic performance for CO oxidation was evaluated through the feeding gas with or without water vapor. The results showed that the activity and the stability of MO x catalysts are greatly dependent on the kinds of metal oxides. The activity order of MO x is Co 3O 4>NiO>Fe 2O 3>CuO>MnO x>ZnO>Al 2O 3>Cr 2O 3>CaO>La 2O 3. The water has negative effect on the activity of MO x (M=Co, Cu, Fe, Mn, Ni and Zn) catalysts. The catalytic activity and stability of Au/MO x catalysts are greatly dependent on the properties of MO x. The water has negative effect on the activity of Au/MO x (M=Ca, Cr, Cu,La and Mn) and on the stability of Au/MO x (M=Al, Co, Fe, Mn, Ni and Zn) at ambient temperature.
