A series of CeO2/SiO2 and SixCe1-xO2 complex oxides supported on an activated Al2TiO5-TiO2-SiO2 complex phase (ATS) ceramics were prepared by step impregnation and co-impregnation methods, and characterized by N2-BET, XRD, SEM and NH3-TPD techniques. The effects of reaction temperature, CeO2/SiO2 loadings and Si/Ce molar ratio on the granular catalysts for NO selective catalytic reduction with ammonia (NH3-SCR) were studied. Results indicated that both CeO2/SiO2/ATS and CeO2/ATS catalysts showed the same active temperature window of 250-300 oC, mainly depending on the chemical composition of ceria. Moreover, the SixCe1-xO2/ATS catalysts exhibited higher activity and stability than those of CeO2/SiO2/ATS, and the Si0.75Ce0.25O2 represented the highest activity of 88.70% at 300 oC and the broadest active temperature window of 250-400 oC. Furthermore, the NH3-SCR of NO over the SixCe1-xO2 complex oxide catalysts was a result from synergetic catalysis between the acid catalysis and the redox catalysis.
The promotional effect of the interaction between titania and ceria on the catalytic performance for selective reduction of NO was studied.The catalysts,CeO 2,TiO 2,CeO 2 /TiO 2 and Ti x Ce 1-x O 2,were synthesized and tested in NH 3-Selective catalytic reduction(SCR) of NO,and the samples were characterized by the Brunaller,Emmett and Teller(BET absorbed gas N 2),X-ray diffraction(XRD),high resolution transmission electron microscopy(HR-TEM),and temperature programmed desorption(TPD NH 3) techniques.The improvement mechanism of the interaction between the titania and ceria had been explored and discussed from two aspects of micro-structure and surface acidity.The interaction between the titania and ceria greatly improved the catalytic activity but had little effect on the active temperature.It was first reported that the acid amount determined the catalytic activity and the acid strength determined the active temperature for NH 3-SCR of NO.
