High Efficient CoO_x-MnO_x Catalysts For Lowtemperature Selective Catalytic Reduction Of NO With NH₃

NOx emission is one of major air pollutants that can cause a wide variety of health and environmental problems such as Ground-level Ozone(Smog)Acid Rain, Global Warming,Visibility Impairment. Thereby NOx emission control has received widespread attention. Currently, the method of the selective catalytic reduction(SCR) of NOx using ammonia/urea as the reducing agent is the most widely used and most efficient method for controling NOx emission. While the development of efficient catalysts that can perform well at low temperature has been concerned to solve the problems of energy loss in the operation of the SCR process at high temperature, and deactivation of the vanadium catalysts due to high concentrations dust and sulfur compound.In this project, a series of Co/Mn mixed oxide(Co Ox-Mn Ox) catalysts were synthesized by using a co-precipitation method and their performance in catalyzing the low-temperature selective catalytic reduction of NOx with NH3 were investigated. The results demonstrated that the addition of Co Ox can significantly enhance the catalytic activity of Mn Ox. Co Ox-Mn Ox catalysts with the molar ratio between Co and Mo of 4:6 and calcined at 400 °C exhibited the best catalytic performance. In this work, NOx conversion on the(Co Ox-Mn Ox) catalysts can nearly reach 100% at the temperature range of 210-240 oC. Co(0.4)-Mn Ox(400) exhibited high specific surface area and low crystalline structure. H2-TPR and NH3-TPD results confirmed the better low temperature reducibility property and high acidity on surface of Co-Mn Ox mixed oxides catalysts. The chemical states and atom concentration on the surface of catalysts were investigate by XPS analyses...