A novel Cerium-Tin composite oxide catalyst with high SO2 tolerance for selective catalytic reduction of NOx with NH3

The selective catalytic reduction for reducing NOx with NH3 (NH3-SCR) has been widespread used in denitration. Considering the shortcomings of vanadium-based catalysts, a series of novel CeO2-SnO2 composite oxide catalysts with good SO2 tolerance were developed. The effects of preparation methods on the catalytic performance had been systematically studied by characterization methods, such as XRD, SEM, N2 adsorption-desorption, H2TPR, NH3-TPD, XPS and in situ Fourier transform infrared spectroscopy (FTIR). Characterization results concluded that the catalytic performance was closely related to the different physicochemical property resulting from preparation methods. CeO2-SnO2 composite catalyst was prepared by coprecipitation method (CeSn-CP) that displayed high NH3-SCR activity and good SO2 tolerance. The coprecipitation method resulted in the high dispersion of SnO2 species and the formation of binary solid solution. Binary solid solution was beneficial to play the synergetic effect between CeO2 and SnO2, which had improved reduction ability and acidity, and thus an apparent promotion of activity was presented.