MnO{sub x}-Nb{sub 2}O{sub 3}-CeO{sub 2} - A New Catalyst For Low-Temperature SCR With Reduced N{sub 2}O Formation

MnOx-CeO2 was found to be up to 5 times more active for the selective catalytic reduction of NO{sub x} with ammonia (SCR) than the established V{sub 2}O{sub 5}/WO{sub 3}-TiO{sub 2} catalysts at temperatures below 250 C. The SCR activity of MnO{sub x}-CeO{sub 2} itself was further improved by a factor of 1.3-65 by the addition of Nb{sub 2}O{sub 3}, depending on the temperature (125-350 C). Moreover, a strong decrease in the selectivity to the side-product N{sub 2}O was observed, especially in the low-temperature range. (author)