CO2 reforming of methane to produce synthesis gas was examined in a fixed bed reactor, using a combined nickel-cobalt based catalyst supported on a mixed oxide (modified alumina with ZrO2) obtained by the sol-gel method. The loading of nickel and cobalt was kept at 0.0500 g/g (1:1), while the amount of Ir varied between 0.0000 to 0.0100 g/g. The reforming reactions were performed at 700 degrees C. The time on stream profile for 360min showed that all catalysts were very active and stable. The promoter doping of 0.0250 g/g Co-0.0250 g/g Ni-Xg/g Ir/(Al2O3-ZrO2) catalysts augmented the activity regarding the CH4 and CO2 by 20 %. The catalysts were characterized by means of TGA, TPR, TPD, XRD, and SEM. The TGA and TPR results showed that the promoter depressed the carbon deposition and upgraded the reducibility of the active metals in that order. While the TPD analysis illustrated the basic sites of the catalyst are of medium strength.