Effect of Cu doping on the SCR activity of CeO2 catalyst prepared by citric acid method

CeO2–CuO catalyst prepared by citric acid method was investigated for selective catalytic reduction of NO with NH3. The activity of the CeO2 catalyst was enhanced about 8–27% in the temperature range of 125–225 °C at a space velocity of 28,000 h−1 by the addition of Cu. It was found that the state of Cu species had great impact on the SCR performance of CeO2–CuO catalyst. Cu2+ can enhance the low temperature activity of SCR reaction, while CuO would promote NH3 oxidation before SCR reaction at high temperature, which would cause the decrease of its high temperature SCR activity.