A comparative study of the selective oxidation of NH_3 to N_2 over transition metal catalysts

摘要

CU-Mn/Al_2O_3, 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/TiO_2 has the highest NH3 conversion and highest NO, NO_2 yield. 5%Cu-5%Mn/Al_2O_3 is a promising NH3 selective catalytic oxidation catalyst, but still needs further study. SBA-15 is a bad support for Cu-Mn. Al_2O_3-based catalysts and TiO_2-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/Al_2O_3 is better than Cu-Mn/TiO_2, but NH_3 conversion on Cu-Zr/TiO_2 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.