Manganese-cerium oxide (MnOx-CeO2) catalysts supported by titanium-bearing blast furnace slag for selective catalytic reduction of nitric oxide with ammonia at low temperature

Abstract

A series of manganese-cerium oxide (MnOx-CeO2) catalysts supported by Ti-bearing blast furnace slag were prepared by wet impregnation and used for low-temperature selective catalytic reduction (SCR) of NO with NH3. The slag-based catalyst exhibited high nitrogen oxide removal (deNOx) activity and wide effective temperature range. Under the condition of NO = 500 ppm, NH3 = 500 ppm, O-2 = 7-8 vol%, and total flow rate = 1600 mL/min, the Mn-Ce/Slag catalyst exhibited a NO conversion higher than 95% in the range of 180-260 degrees C. The activity of Mn/Slag catalysts was greatly enhanced with the addition of CeO2. The results indicated that Ti-bearing blast furnace slag had suitable phase composition as good support of SCR catalyst. Implications: Ti-bearing blast furnace slag is a kind of industrial waste in China. Much slag was underused and piling up, which could cause many environmental issues, such as enormous waste of titanium and groundwater and soil contamination by heavy metals in leachates. The utilization of slag as the support of SCR catalyst will not only make use of solid waste but also cut down the NOx emitted from power plant.