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催化学报 2010
铂和HF掺杂的H-ZSM-5分子筛催化甲苯与甲醇烷基化反应, PP. 1209-1216 Keywords: methanol,toluene,alkylation,platinum,hydrofluorination,shape-selectivity,ZSM-5 Abstract: ？Toluenewasalkylatedwithmethanolinaflowtypereactorattemperaturesbetween300and500°CusingH-ZSM-5zeolite,0.2%Pt/H-ZSM-5andhydrofluorinated0.2%Pt/H-ZSM-5withHFconcentrationsof1.0%,2.0%,3.0%,or4.0%.Ptprimarilyenhancestolueneconversion,totalxylenesproduction,andp-xylenerelativetoitsthermodynamicequilibrium.AstheconcentrationofHFincreasesfrom1.0%to3.0%,thecatalystactivityincreasesbecauseoftheincreaseinthenumberofacidsitesandtheirstrength.Additionally,thesurfaceareaandPtdispersionalsoincreases.AnadvantageofincreasedHFdopingisthattheformationofvoluminoustrimethylbenzene(TMB)byproductsisinhibited.However,ataHFconcentrationof4.0%,AlandSiarepartiallyleachedandthendepositedmostlyinthewidercatalyticpores.Thiswasdeterminedbyevaluatingtheporevolumedistributionandwedeterminedthatreactivityinhibitionwasob-viouslypresentandwasduetodiffusionrestriction.
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