A new type of catalyst for ammonia selective catalytic oxidation, mesoporous CuO/RuO2 with well-crystallized framework and ordered mesoporous structure, has been synthesized by a co-nanocasting-replication method. Various techniques have been employed for the material characterization. The prepared mesostructured bimetal oxides demonstrated high catalytic activity and N-2 selectivity toward NH3 oxidation reaction in the presence of excess oxygen. The temperature for the complete ammonia oxidation was as low as 180 degrees C on the mesoporous 10 wt.% CuO/RuO2 composite, and there was no apparent decrease in the catalytic activity at prolonged reaction time. Both high ammonia conversion up to 100% and high N-2 selectivity (>95%) were achieved on the mesoporous 5-15 wt.% CuO/RuO2 composites. A synergetic catalytic mechanism between copper and ruthenium component was proposed to understand the promoted catalytic effect, especially the achievement of both high conversion and high selectivity for N-2 by CuO. (C) 2010 Elsevier Inc. All rights reserved.