摘要：A series CeO2（ZrO2）/TiO2 catalysts were modified with Er using a sol-gel *** catalytic activity of the obtained catalysts in the selective catalytic reduction（SCR） of NO with NH3 was investigated to determine the appropriate Er *** catalysts were characterized using X-ray diffraction,N2 adsorption,NH3 temperature-programmed desorption,H2 temperature-programmed reduction,photoluminescence spectrosco.y,electron paramagnetic resonance spectrosco.y,and X-ray photoelectron *** results showed that the optimum Er/Ce molar ratio was 0.10;this catalyst had excellent resistance to catalyst poisoning caused by vapor and sulfur and gave more than 90% NO co.version at 220–395 ℃ and a gas hourly space velocity of 71 400 h^-*** inco.poration increased the Ti^3＋ co.centrations,oxygen storage capacities,and oxygen vacancy co.centrations of the catalysts,resulting in excellent catalytic *** inco.poration also decreased the acid strength and inhibited growth of TiO2 and CeO2 crystal particles,which increased the catalytic *** results show that high oxygen vacancy co.centrations and oxygen storage capacities,large amounts of Ti^3＋,and low acid strengths give excellent SCR activity.