The Study On Catalytic Combustion Properties Of Methane Over Double Perovskite Catalysts

A series of double perovskite catalysts Sr₂B'B"O₆(B'=Fe,Co,Ni,Mn,Cr, B"=Mo,W) were prepared by sol-gel method with citric acid as complex agent. Theproperities and structure of catalysts were characterized by XRD, TPR, BET, XPS,Electrical conductivity Test. Catalytic activities in methane catalytic combustion ofcatalysts were investigated.The results showed that main-phase double perovskites could be preparedefficiently by sol-gel method at the temperature 1100℃in H₂5ï¼…/N₂95ï¼…mixedatmosphere concluding single-phase double perovskites Sr₂FeMoO₆,Sr₂MnMoO₆,Sr₂FeWO₆,Sr₂CoWO₆,Sr₂NiWO₆. La and Ce doped double perovskites oxides Sr_2-xLa_xMnMoO₆ (x=0.02,0.04,0.06,0.08,0.10)and Sr_2-xCe_xMnMoO₆(x=0.02,0.04,0.06,0.08,0.10)wereprepared by the same method. It indicated that an optimal quantity of La dopingdouble perovskite oxide catalysts Sr₂MnMoO₆ can improve its catalytic activitysignificantly and Ce doping double perovskite oxide catalysts Sr₂MnMoO₆ wasdisadvantage for its activity. When X≤0.08, it is advantage for forming single-phasedouble perovskite Sr_2-xLa_xMnMoO₆, and when X≤0.06 it is good for formingsingle-phase double perovskite Sr_2-xCe_xMnMoO₆.