Applied Catalysis A: General, Vol.570, 251-261, 2019
Effect of Cu doping on the SCR activity over the CumCe0.1-mTiOx (m=0.01, 0.02 and 0.03) catalysts
A series of Ce0.1TiOx, Cu0.1Ox and CumCe0.1-mTiOx (m = 0.01, 0.02, 0.03) catalysts are prepared via a sol-gel method for the selective catalytic reduction (SCR) of NO with NH3. The samples are mainly characterized by Xray diffraction (XRD), Raman, H-2-TPR, NH3-TPD, separated NO/NH3 oxidation, X-ray photoelectron spectroscopy (XPS) and in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) to investigate the properties of the catalysts. Among the CumCe0.1-mTiOx (m = 0.01, 0.02, 0.03) catalysts, Cu0.01Ce0.09TiOx displays much better catalytic activity in the range of 170 degrees C-425 degrees C ( > 90% NO conversion), N-2 selectivity and resistance of SO2 and H2O even at high gas hourly space velocity. The XPS results verify that the introduction of Cu leads to a copper species enrichment environment and the formation of more surface Ce3+ and absorbed oxygen (O-alpha), which are in favor of the oxidation of NO to NO2, enhancing the activity at low temperature. Furthermore, in situ DRIFTS results confirm that the Langmuir-Hinshelwood (L-H) mechanism is predominant in the NH3-SCR process for the Cu0.01Ce0.09TiOx catalyst at 150 degrees C.