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

CeO 2 –CuO catalyst prepared by citric acid method was investigated for selective catalytic reduction of NO with NH 3 . The activity of the CeO 2 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 CeO 2 –CuO catalyst. Cu 2+ can enhance the low temperature activity of SCR reaction, while CuO would promote NH 3 oxidation before SCR reaction at high temperature, which would cause the decrease of its high temperature SCR activity.