A novel catalyst of silicon cerium complex oxides for selective catalytic reduction of NO by NH3

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 °C, 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 °C and the broadest active temperature window of 250–400 °C. 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.