Supported LaCoO3 perovskites with 10 and 20 wt.% loading were obtained by incipient wetness impregnation of different Ce1-xZrxO2 (x = 0-0.3) supports with a "citrate" solution, prepared from La and Co nitrates, and citric acid. Ce1-xZrxO2 were also prepared using the "citrate method". All materials were calcined at 700 degrees C for 6 h and investigated by N-2 adsorption at -196 degrees C, XRD and XPS. XRD patterns evidenced the formation of a pure perovskite phase. These materials were tested in toluene total oxidation in the temperature range 100-500 degrees C. All catalysts showed a lower T-50 than the corresponding Ce1-xZrxO2 supports or pure LaCO03 perovskite. The activity of the catalysts was found to increase with the perovskite loading, irrespective of the support composition. For the same loading, the support composition influences drastically the oxidative abilities of LaCoO3. (c) 2005 Elsevier B.V. All rights reserved.