CO2 reforming and partial oxidation of methane were carried out using Pt/Al2O3, Pt/ZrO2, and Pt/10%ZrO2/Al2O3 catalysts, in the temperature range 450-900degreesC. The Pt/10%(ZrO2Al2O3)-Al-/ was found to be the most active and stable catalyst for combined CO2 reforming and partial oxidation of methane. The addition of O-2 to the feed increases CH4 conversion and the catalyst stability. The deactivation is primarily due to coke formation, which was characterized by thermogravimetric analysis and transmission electron microscopy. The reduction of carbon deposition over zirconia-alumina catalyst is related to Pt-Zrn+ interactions and the high oxygen mobility on zirconia. (C) 2003 Elsevier B.V. All rights reserved.