学科分类
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5 个结果
  • 简介:ThreeseriesofCeO2/CuOsampleswerepreparedbyimpregnationmethodandcharacterizedbyXRD,N2adsorption-desorption,temperatureprogrammedreduction(TPR),XPSandTEMtechniques.IncomparisonwiththesamplespreparedwithCuOasinitialsupport,thesampleswithCu(OH)2asinitialsupporthavehigherreducibilitiesandsmallerrelativeTPRpeakareas,andalsolargerspecificsurfaceareasatcalcinationtemperaturesof400℃–600℃.Asaresult,Cu(OH)2isbetterthanCuOasinitialsupportforpreferentialoxidationofCOinexcessH2(CO-PROX).Thebestcatalyticperformancewasachievedonthesamplecalcinedat600℃andwithanatomicratioofCe/Cuat40%.XPSanalysesindicatethatmoreinterfacelinkagesCe-O-Cucouldbeformedwhenitwascalcinedat600℃.AndtheatomicratioofCe/Cuat40%ledtoaproperreducibilityforthesampleasillustratedbytheTPRmeasurements.

  • 标签: 氧化铜催化剂 选择性氧化 氧化铈 支护效果 二氧化碳 程序升温还原
  • 简介:ThemorphologyeffectofZr-dopedCeO2wasstudiedintermsoftheiractivitiesintheselectiveoxidationofstyrenetostyreneoxideusingtert-butylhydroperoxideastheoxidant.Inthepresentwork,ZrdopedCeO2nanorodsexhibitedthehighestcatalyticperformance(yieldofstyreneoxideandTOFvalue)followedbynanoparticlesandnanocubes.FortheZr-dopedCeO2nanorods,theapparentactivationenergyis56.3kJ/mol,whichismuchlowerthanthevaluesofcatalystssupportedonnanoparticlesandnanocubes(73.3and93.4kJ/mol).Thehighresolutiontransmissionelectronmicroscopyresultsindicatedthat(100)and(110)crystalplanesarepredominantlyexposedforZr-dopedCeO2nanorodswhile(100)and(111)fornanocubes,(111)fornanoparticles.TheremarkablyincreasedcatalyticactivityoftheZrdopedCeO2nanorodsismainlyattributedtothehigherpercentageofCe3+speciesandmoreoxygenvacancies,whichareassociatedwiththeirexposed(100)and(110)crystalplanes.Furthermore,recyclingstudiesprovedthattheheterogeneousZr-dopedCeO2nanorodsdidnotloseitsinitialhighcatalyticactivityafterfivesuccessiverecycles.

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  • 简介:CuO-CeO2catalystswerepreparedbyaureaprecipitationmethodfortheoxidativesteamreformingofethanolatlow-temperature.Thecatalyticperformancewasevaluatedandthecatalystswerecharacterizedbyinductivelycoupledplasmaatomicemissionspectroscopy,X-raydiffraction,temperature-programmedreduction,fieldemissionscanningelectronmicroscopyandthermo-gravimetricanalysis.OverCuOCeO2catalysts,H2withlowCOcontentwasproducedinthewholetestedtemperaturerangeof250–450C.Thenon-noblemetalcatalyst20CuCeshowedhigherH2productionratethan1%Rh/CeO2catalystat300–400Candtheadvantagewasmoreobviousafter20htestingat400C.TheseresultsfurtherconfirmedthatCuO-CeO2catalystsmaybesuitablecandidatesforlowtemperaturehydrogenproductionfromethanol.

  • 标签: CuO-CeO2 catalyst hydrogen production OXIDATIVE steam