A Comparative Study of the Selective Oxidation of NH3 to N2 over Transition Metal Catalysts

Cu-Mn/Al₂O₃, Cu-Mn/TiO₂ and Cu-Mn/SBA-15 were prepared by incipient wetness impregnation. The activity of those catalysts for selective catalytic oxidation (SCO) of ammonia to nitrogen at low temperature (100°C~250°C) is not so satisfying. 5%Cu-5%Zr/TiO₂ has the highest NH₃ conversion and highest NO, NO₂ yield. 5%Cu-5%Mn/Al₂O₃ is a promising NH₃ selective catalytic oxidation catalyst, but still needs further study. SBA-15 is a bad support for Cu-Mn. Al₂O₃-based catalysts and TiO₂-based catalysts were also prepared by incipient wetness impregnation to sure the synergistic effect between transition metal. The results find the activity on Cu-Mn/Al₂O₃ is better than Cu-Mn/TiO₂, but NH₃ conversion on Cu-Zr/TiO₂ is rather well with high yield of NO. The role of supports and transition metals play in catalyst are discussed by a series of experiments. Key ward: SCO, NH₃, transition metal, γ-Al₂O₃, TiO₂, SBA-15