Nickel catalysts supported on different amounts of SrO modified SiO2 were prepared and used in combined dry reforming and partial oxidation of methane in a fluidized bed reactor. This reaction was investigated under different temperatures, space velocities and feed gas composition. Results showed that the structure of the nickel active phase strongly depended on the interaction between Ni and the support, which was related to the support properties, the additives and the preparation methods. The catalysts were characterized using XRD, TPR, CO2-TPD and TEM techniques. Ni sintering was a major reason for the deactivation of pure Ni/SiO2 catalysts, while Ni dispersed highly on a 10 wt% Sr promoted Ni/SrO-SiO2 catalyst. The enhanced interaction between Ni species and SrO-promoted support might be responsible for its high activity and good resistance to agglomeration of the nickel particles. (C) 2004 Published by Elsevier Ltd on behalf of the International Association for Hydrogen Energy.