简介:Selectivecatalyticoxidation(SCO)ofammoniawascarriedoutoverCu-MncompoundscatalystsmodifiedwithtrivalentrareearthoxideCe2O3andLa2O3respectively.TiO2wasusedassupportanddifferentratioofO2weretestedinordertofindanappropriateO2concentration(vol.%),andtheresultsshowedthat1%O2(vol.%)waspropitioustoSCOofammonia.TheeffectsofthetworareearthoxidesmodifiedcatalystsCe2O3-Cu-Mn/TiO2andLa2O3-Cu-Mn/TiO2onthecatalyticactivityandselectivityofammoniaoxidationwereinvestigatedunderthereactionconditionof500ppmammonia,1%O2(vol.%),atthetemperaturefrom125to250oC.TheresultsrevealedthebeneficialroleofCe2O3andLa2O3incatalyticactivityatlowtemperatureandleanoxygenconcentration,whilethemodificationwithCe2O3andLa2O3ledtothenegativeinfluenceonN2selectivity.ForthecatalystsmodifiedwithCeshowedlowerNOandN2OselectivitythanthecatalystsmodifiedwithLa,thentheeffectsofdifferentCeloadingsoncatalyticactivityandselectivitywerealsoconsidered,incombinationwithcatalystspreparationmethods,whichincludeincipientwetimpregnation,sol-gelmethodandco-precipitation.Resultsrevealedthatthecatalystspreparedbysol-gelmethodobtainedpreferablecatalyticactivitycomparedwiththeothers,reaching99%ammoniaat200oC,whereas96%NOwasdetected.Italsoindicatedthatdifferentcatalystpreparationmethodsignificantlydeterminedproductiondistribution.