Environmental-friendly production of FeNbTi catalyst with significant enhancement in SCR activity and SO_2 resistance for NO_x removal

摘要

An environmental-friendly FeNbTi catalyst with different Nb doping was investigated for NH3-SCR reaction at low temperature, which exhibited excellent activity and tolerance to SO2 and H2O poisoning. A series of characterization were used to investigate the reasons for the high activity and SO2 resistance of the catalyst before and after Nb modification, such as BET, XRD, XPS, H-2-TPR, O-2-TPD, NH3-TPD, NO-TPD and DRIFT. XRD and XPS results displayed that the doping of Nb could promote the speciation transformation of Fe2O3 from crystalline to amorphous phase and more chemisorbed oxygen species generated. In addition, NH3-TPD and NO-TPD results suggested that the amount of surface acid sites and NO chemisorption increased after Nb doping, and the adsorption and oxidation of NH3 or NO improved through DRIFT analysis. All these factors contributed to the outstanding SCR performance and strong resistance to SO2 and H2O.