Activity of -Al۲O۳-based Mn, Cu, and Co oxide nanocatalysts for selective catalytic reduction of nitric oxide with ammonia

چکیده مقاله

Our studies on the selective catalytic reduction of NO (SCR-deNO) properties of M/ -Al2O3 (M = Mn, Co, Cu) nanocatalysts are presented. All catalysts were prepared by homogeneous deposition precipitation using urea as the precursor for the precipitating agent. The SCR activity followed the order Mn/ -Al2O3 > Cu/ -Al2O3 > Co/ - Al2O3 . The nanocatalysts were characterized with respect to their texture (N2 -BET), particle size (TEM), reducibility (H2 -TPR), and acidity (NH3 -TPD). The TEM analysis revealed that the metal species have superior dispersion with less agglomeration and sintering on -Al2O3 support. The H2 -TPR results conrmed that the Mn/ -Al2O3 nanocatalyst contains various oxidation states of manganese, which is useful for the catalyst to maintain the DeNO activities. The NH3 -TPD studies indicated that the addition of transition metal can signicantly increase the surface acidity and Mn/ -Al2O3 showed the most adsorbed sites of NH3 . Characterization results indicated that the acidity and the redox properties of the catalyst play important roles in thenal catalytic activity in the SCR-NO process.