In this paper, the effects of K2O promoter on the activity, stability, and coke deposition of nickel catalysts supported on mesoporous nanocrystalline zirconia powder with high surface area and pure tetragonal crystallite phase were investigated in methane reforming with carbon dioxide. The samples were characterized by X-ray diffraction (XRD), BET surface area, temperature-programmed techniques (TPR, TPO, TPH, TPD), and scanning electron microscopy (SEM). The obtained results showed that the addition of K2O promoter affected the catalyst structure, increased the activity and stability, and also reduced the coke deposition on the catalysts.