The oxidation of ammonia to nitrogen by selective catalytic oxidation (NH3-SCO) over a bimetallic CuO/CeO2 nanoparticle catalyst at temperatures between 423 and 673K. A bimetallic CuO/CeO2 nanoparticle catalyst was prepared by co-precipitation method at molar ratio of 6:4. This study also considers how the concentration of influent NH3 (C0 = 800 ppm), the space velocity (GHSV = 92000/hr), the relative humidity (RH = 12%) and the concentration of oxygen (O2 = 4%) affect the operational stability and the capacity for removing NH3. The catalysts were characterized before and after reaction using EDX, BET, ATR-FTIR, PSA and TEM. The catalytic performance show that the ammonia was removed by oxidation in the presence of bimetallic CuO/CeO2 nanoparticle catalyst, and around 98% at complete NH3 reduction was achieved, and a high selectivity toward N2 during catalytic oxidation over the catalyst at 673K with an oxygen content of 4.0%. Moreover, the effect of the reaction temperature on the removal of NH3 in the gaseous phase was also monitored at a gas hourly space velocity of under 92000/hr.