[en] Various types of metal oxides with the perovskite structure were synthesized. In the ABO3 type with A = La and B = Co, Mn, part of the A-cations were substituted by Sr or Ce. A2BO4 oxides with A = La, B = Co were prepared as well and partially substituted by Sr. Finally, double perovskites were investigated. The catalytic effect of the oxides were tested for oxidation of hydrocarbons and CO and for the reduction of NO using automobile exhaust gas. The catalysts of the ABO3-type showed the best activity