Microwave Irradiation Coupled with MeOx/Al2O3 (Me = Cu,Mn,Ce) Catalysts for Nitrogen Monoxide Removal from Flue Gas at Low Temperatures

The direct catalytic decomposition of nitrogen monoxide (NO) into nitrogen (N-2) and oxygen (O-2) with high efficiency remains a significant challenge at low temperatures under excess oxygen conditions. Herein, we report the direct decomposition of NO by microwave-assisted catalysis over metal oxide catalysts MeOx/Al2O3 (Me = Cu, Mn, Ce) for the first time under these conditions. The CeCuMnOx/Al2O3 catalyst displays an impressively high efficiency with a high NO conversion and N-2 selectivity, reaching up to 94.8 % and 98.7 %, respectively, even at a low temperature of 250 degrees C and oxygen excess of 10 %. Moreover, the cerium-doped MeOx/Al2O3 (Me = Cu, Mn) catalysts enhance the catalytic performance dramatically, and CeCuMnOx/Al2O3 is more active than CeCuOx/Al2O3 and CeMnOx/Al2O3 under microwave irradiation. Comparatively, these catalysts show extremely low catalytic activity under conventional reaction conditions. Furthermore, the catalytic performance of NO decomposition under microwave irradiation is hardly influenced by the oxygen concentration.