摘要
WhileFe-basedoxygencarriers(OC)areregardedtobepromisingforchemicalloopingcombustion(CLC),thedecreaseofCO2selectivityduringdeepreductionprocessandthesevereagglomerationofFe2O3oftenoccuraftermultipleredoxcyclesduetothelowoxygenmobility.Herein,Fe-substitutedBahexaaluminates(BaFexAl12–xO19,denotedasBFxA-H,x=1and2)preparedbyamodifiedtwo-stepmethodexhibitednotonlyhigheramountofconvertedoxygen(Ot)andCH4conversion(77%and81%vs.17%and75%)thanthosepreparedbythetraditionalco-precipitationmethod(BFxA-C,x=1and2)butalsohighCO2selectivityabove92%duringthenearlywholereductionfromFe3+toFe2+.Furthermore,theBFxA-Hexhibitedtheexcellentrecyclabilityduring50cycles.ThebetterperformancewasascribedtothemarkedlyenhancedoxygenmobilitywhichresultedfromdominantoccupancyofFecationsinAl(5)sites(Fe5:71%and70%vs.49%and41%)inmirrorplanesofhexaaluminateleadingtolargeramountoflatticeoxygencoordinatedwithFe5(O–Fe5)(0.45and0.85mmol/gvs.0.31and0.50mmol/g).TheimprovementofoxygenmobilityalsofavoredthepreservationofchemicalstateofFecationsinhexaaluminatestructureinthere-oxidationstep,resultingintheexcellentrecyclabilityofBFxA-H.
出版日期
2019年02月12日（中国期刊网平台首次上网日期，不代表论文的发表时间）
