Selective catalytic reduction of NOx with NH3 over Mn-Ce mixed oxide catalyst at low temperatures

Abstract

A series of Mn-Ce mixed oxide catalysts with different molar ratio of Mn/Ce were prepared by the surfactant-template (ST) method and conventional co-precipitation (CP) method for the selective catalytic reduction of NOx with ammonia (NH3-SCR) at low temperatures. Catalyst preparation method exerts significant influence on the catalytic performance, and Mn-Ce mixed oxide catalyst prepared by ST method is more active than that prepared by CP method. The best Mn-Ce mixed oxide catalyst prepared by ST method yielded nearly 100% NOx conversion in the temperature range of 100–200°C. Moreover, its resistance against H2O and SO2 is higher. The high surface area of Mn-Ce mixed oxide catalyst prepared by the ST method could contribute to the adsorption and activation of NH3 as well as NOx, thus promoting the NOx reduction to proceed.