Activity of mesoporous-MnOx (m-MnOx) and CuO/m-MnOx for catalytic reduction of NO with CO

The direct reduction of NO over mesoporous manganese oxide (m-MnOx) and in the presence of CO was studied at reaction temperatures in the range from 150 to 460 degrees C. The conversion of NO without the reducing agent CO was limited to less than 10%, but when CO was added to the reactor feed up to 70% of the NO was reduced at a reaction temperature of 340 degrees C. However, the m-MnOx catalyst activity deteriorated at temperature above 340 degrees C due to a transformation of MnO2 to the less active Mn2O3 and Mn3O4 phases. The activity of the m-MnOx catalyst at high temperatures was enhanced by the addition of CuO. Two methods to load CuO on the m-MnOx were investigated: wet impregnation and co-precipitation. Both methods produced catalysts that achieved close to 97% NO conversion in CO at a reaction temperature of 430 degrees C. (C) 2012 Elsevier B.V. All rights reserved.