ZrO2-supported α-MnO2:Improving low-temperature activity and stability for catalytic oxidation of methane

The single phaseα-Mn O2and in-situ supportedα-Mn O2/Zr O2with different ratios of Mn/Zr were synthesized by one-pot hydrothermal method.They showed superior activity for catalytic oxidation of methane and even better than that of 1%Pt/Al2O3.The T50of Mn O2/Zr O2catalysts with different ratios of Mn/Zr were located in the range of 315–335°C at a WHSV of 90 L g-1h-1,whereas that of Pt/Al2O3was 380°C.After sulfur ageing,the Mn O2/Zr O2catalysts with Mn/Zr ratio of 2:1(2Mn O2/1Zr O2)and 1:1(1Mn O2/1Zr O2)exhibited satisfying sulfur resistance in comparison to the pure Mn O2.The 2Mn O2/1Zr O2catalyst also showed acceptable catalytic stability,and the addition of 10 vol%CO2had no obvious negative effect on its stability,whereas the addition of2.6 vol%H2O caused slight but reversible decreasing methane oxidative activity.