Selective catalytic oxidation of ammonia to nitrogen over mesoporous CuO/RuO2 synthesized by co-nanocasting-replication method

Abstract

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 N2 selectivity toward NH3 oxidation reaction in the presence of excess oxygen. The temperature for the complete ammonia oxidation was as low as 180 °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 N2 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 N2 by CuO.