The diesel soot combustion was studied using catalysts prepared by impregnation with cesium nitrate and/or gold on zirconium oxide (ZrO2), hydrated zirconium oxide and silica (SiO2). Catalysts were characterized by colorimetry, elemental analysis, atomic absorption spectrophotometry, XRD, FTIR, TPR and XPS. Measurements of catalytic activity were performed in a thermobalance with air and in a fixed bed reactor with a NO/O-2 feed. All catalysts containing cesium nitrate exhibit a good activity for soot oxidation and the addition of gold substantially increases the CO2 generation leading the selectivity to 100% in CO2. (C) 2010 Elsevier B.V. All rights reserved.