MnOx–CeO2/Activated Carbon Honeycomb Catalyst for Selective Catalytic Reduction of NO with NH3 at Low Temperatures

Activated carbon honeycomb supported manganese and cerium oxides (MnO x –CeO 2 /ACH) catalysts were investigated for selective catalytic reduction (SCR) of NO at low temperatures of 80–200 °C. Compared with ACH supported manganese oxide catalyst (MnO x /ACH), MnO x –CeO 2 /ACH catalysts show much higher SCR activity and higher selectivity to N 2 . NO conversion can be improved by the addition of CeO 2 from less than 50% to 100% at 80–160 °C. The N 2 selectivity of higher than 99.8% is obtained over the Ce(1)Mn/ACH catalyst at 80–200 °C. Results indicate that the addition of CeO 2 improves the distribution of MnO x and enhances the oxidation of NO to NO 2, producing more absorbed NO 3 – on the catalyst surface, which is then reduced into N 2 by NH 3 . These behaviors account for the promoting effect of CeO 2 on the SCR activity.