Comparative Study of ZSM-5 Supported Transition Metal (Cu, Mn, Co, and Fe) Nanocatalysts in the Selective Catalytic Reduction of NO with NH3

H-ZSM-5 was modified with transition metals (including Fe, Cu, Mn, and Co) by homogeneous deposition precipitation (HDP) method and tested as catalyst for the selective reduction of NO with ammonia (NH3-SCR). The selectivity to N-2 was higher than 95% in all the nanocatalysts and the NO conversion over nanocatalysts decreased in the following sequence Cu-ZSM-5 > Mn-ZSM-5 > Co-ZSM-5 > Fe-ZSM-5 at 200-300 degrees C. The Cu-ZSM-5 catalyst showed the highest catalytic activity, 95% of NO conversion at 300 degrees C, among the catalysts investigated. The nature of the active sites was characterized by BET, TEM, H-2-TPR, and NH3-TPD. Characterization results revealed that acidity and the redox properties of the catalysts play an important role in achieving high activity for NH3-SCR reaction. The highest catalytic activity of Cu/ZSM-5 can be correlated to easy reducibility of Cu species and strong acidic sites created by the Cu species. (c) 2017 American Institute of Chemical Engineers