The partial oxidation of methane to synthesis gas was studied at atmospheric pressure and in the temperature range of 550-800(degrees)C over alpha-Al2O3-supported bimetallic Pt-Co, and monometallic Pt and Co catalysts, respectively. Both methane conversion and CO selectivity over a bimetallic Pt0.5Co1 catalyst were higher than those over monometallic Pt-0.5 and Co-1 catalysts. Furthermore, the addition of platinum in Pt-Co bimetallic catalysts effectively improved their resistance to carbon deposition with no coking occurring on Pt0.5Co1 during 80 h reaction. The FTIR study of CO adsorption observed only linearly bonded CO on bimetallic Pt-Co catalysts. TPR and XPS showed enhanced formation of a cobalt surface phase (CSP) in bimetallic Pt-Co catalysts. The origins of the good coking resistivity of bimetallic Pt-Co catalysts were discussed.