Effect of ceria doping on SO2 resistance of Mn/TiO2 for selective catalytic reduction of NO with NH3 at low temperature

Mn/TiO2 and ceria modified Mn/TiO2 were prepared by sol–gel method and used for low-temperature selective catalytic reduction (SCR) of NO with NH3 in the presence of SO2. The deactivation of Mn/TiO2 by SO2 was observed during SCR process and the depositions of (NH4)2SO4 and NH4HSO4 were detected on Mn/TiO2 surface. It was found that the resistance to SO2 could be greatly enhanced for Ce modified Mn/TiO2. It was because that the formation of Ti(SO4)2 and Mn(SO4)x was prevented and the depositions of (NH4)2SO4 and NH4HSO4 were significantly inhibited with the doping of ceria.