Selective Catalytic Reduction of Nitric Oxide with Propylene over One-Step Synthesized Cu-SAPO-34 Catalysts

To investigate the performance of Cu-chabazite for selective catalytic reduction of NO with propylene (C3H6-SCR), a series of Cu-SAPO-34 catalysts with varied Cu/Al ratio have been synthesized by the one-pot hydrothermal method. These catalysts were characterized using N-2 adsorption-desorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), temperature programmed reduction by H-2 (H-2-TPR), and in. situ diffuse reflectance infrared Fourier transform spectroscopy (in.situ DRIFTS) techniques. The effect of Cu component on physicochemical properties and C3H6-SCR activity were investigated. Cu-SAPO-34 catalysts with Cu loading (22.76%similar to 4.12%(w/w)) exhibited attractive activities, with nearly 100% NOx conversion and 100% N-2 selectivity at the temperatures (300 similar to 400.) in the excess of oxygen. Based on in situ DRIFT studies, the formation of NO2-/NO3- intermediates requires the presence of isolated Cu2+ ions in Cu-SAPO-34, which undergo a periodic Cu2+/Cu+ redox cycle during C3H6-SCR.