Ultra-deep oxidative desulfurization of fuel with H2O2 catalyzed by phosphomolybdic acid supported on silica

Article abstract of DOI:10.1016/S1872-2067(16)62558-5

A highly active catalyst of phosphomolybdic acid (HPMo) was prepared and applied in the catalytic oxidative desulfurization (CODS) system. The catalyst was characterized by FT-IR, XRD, XPS and superconducting NMR. The influences of m(catalyst)/m(oil), V(H₂O₂)/V(oil), reaction temperature and reaction time on the fractional conversion of benzothiophene (BT) and dibenzothiophene (DBT) were investigated. GC-MS and micro-coulometric methods were employed to investigate the reaction. The catalyst has high desulfurization activity in the removal of BT and DBT under mild conditions. The recycling experiments indicated that DBT and BT removal could still reach 95.2% and 95.7% after 10 cycles.

Full text of DOI:10.1016/S1872-2067(16)62558-5

ChineseꢀJournalꢀofꢀCatalysisꢀ37ꢀ(2016)ꢀ2098–2105
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ꢀ ꢀ ꢀ
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a v a i l a b l e a t w w w . s c i e n c e d i r e c t . c o m
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j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / c h n j c
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Article
2 2
Ultra‐deepꢀoxidativeꢀdesulfurizationꢀofꢀfuelꢀwithꢀH O ꢀcatalyzedꢀbyꢀ
phosphomolybdicꢀacidꢀsupportedꢀonꢀsilicaꢀ
ꢀa
ꢀa,
ꢀa,b
ꢀa
ꢀa
ꢀa
YongshengꢀTian ,ꢀGuanghuiꢀWang *,ꢀJuanꢀLong ,ꢀJiaweiꢀCui ,ꢀWeiꢀJin ,ꢀDanlinꢀZeng
ꢀ
aꢀHubeiꢀKeyꢀLaboratoryꢀofꢀCoalꢀConversionꢀandꢀNewꢀCarbonꢀMaterial,ꢀSchoolꢀofꢀChemistryꢀandꢀChemicalꢀEngineering,ꢀWuhanꢀUniversityꢀofꢀScienceꢀandꢀ
Technology,ꢀWuhanꢀ430081,ꢀHubei,ꢀChinaꢀ
bꢀWuhanꢀHuadeꢀEcotekꢀCorporation,ꢀWuhanꢀ430080,ꢀHubei,ꢀChinaꢀ
A R T I C L E ꢀ I N F O ꢀ
A B S T R A C T ꢀ
Articleꢀhistory:ꢀ
Aꢀhighlyꢀactiveꢀcatalystꢀofꢀphosphomolybdicꢀacidꢀ(HPMo)ꢀwasꢀpreparedꢀandꢀappliedꢀinꢀtheꢀcatalyticꢀ
oxidativeꢀdesulfurizationꢀ(CODS)ꢀ system.ꢀTheꢀcatalystꢀwasꢀcharacterizedꢀbyꢀFT‐IR,ꢀXRD,ꢀXPSꢀandꢀ
Receivedꢀ22ꢀJulyꢀ2016ꢀ
Acceptedꢀ18ꢀSeptemberꢀ2016ꢀ
Publishedꢀ5ꢀDecemberꢀ2016ꢀ
superconductingꢀNMR.ꢀTheꢀinfluencesꢀofꢀm(catalyst)/m(oil),ꢀV(H
andꢀ reactionꢀ timeꢀ onꢀ theꢀ fractionalꢀ conversionꢀ ofꢀ benzothiopheneꢀ (BT)ꢀ andꢀ dibenzothiopheneꢀ
DBT)ꢀwereꢀinvestigated.ꢀGC‐MSꢀandꢀmicro‐coulometricꢀmethodsꢀwereꢀemployedꢀtoꢀinvestigateꢀtheꢀ
2 2
O )/V(oil),ꢀreactionꢀtemperatureꢀ
(
reaction.ꢀTheꢀcatalystꢀhasꢀhighꢀdesulfurizationꢀactivityꢀinꢀtheꢀremovalꢀofꢀBTꢀandꢀDBTꢀunderꢀmildꢀ
conditions.ꢀTheꢀrecyclingꢀexperimentsꢀindicatedꢀthatꢀDBTꢀandꢀBTꢀremovalꢀcouldꢀstillꢀreachꢀ95.2%ꢀ
andꢀ95.7%ꢀafterꢀ10ꢀcycles.ꢀ
Keywords:ꢀ
Mesoporousꢀsilicaꢀ
Phosphomolybdicꢀacidꢀ
Oxidativeꢀdesulfurizationꢀ
Benzothiopheneꢀ
©ꢀ2016,ꢀDalianꢀInstituteꢀofꢀChemicalꢀPhysics,ꢀChineseꢀAcademyꢀofꢀSciences.
PublishedꢀbyꢀElsevierꢀB.V.ꢀAllꢀrightsꢀreserved.
Dibenzothiophene
1
.ꢀ ꢀ Introductionꢀ
less,ꢀthereꢀareꢀtwoꢀdefectsꢀinꢀHDS.ꢀTheꢀHDSꢀprocessꢀisꢀoperatedꢀ
atꢀ overꢀ 300ꢀ °Cꢀ andꢀ hydrogenꢀ pressureꢀ ofꢀ 2–10ꢀ MPaꢀ inꢀ theꢀ
presenceꢀofꢀaꢀsuitableꢀcatalystꢀ(CoMo‐ꢀorꢀNiMo‐basedꢀcatalyst)ꢀ
[10–12],ꢀbutꢀitꢀisꢀconsiderablyꢀdifficultꢀtoꢀreachꢀultra‐lowꢀsulfurꢀ
levels,ꢀespeciallyꢀforꢀDBTꢀandꢀitsꢀderivativesꢀ[13,14].Therefore,ꢀ
itꢀisꢀaꢀchallengeꢀtoꢀdevelopꢀfacileꢀapproachesꢀtoꢀeffectivelyꢀre‐
moveꢀsulfurꢀcompoundsꢀunderꢀmildꢀconditions.ꢀ ꢀ
Asꢀ anꢀ ODSꢀ technique,ꢀ aꢀ catalyticꢀ oxidativeꢀ desulfurizationꢀ
(CODS)ꢀsystemꢀdoesꢀnotꢀneedꢀaꢀhydrotreatingꢀprocessꢀandꢀanꢀ
elevatedꢀtemperature,ꢀandꢀitꢀhasꢀbeenꢀextensivelyꢀstudiedꢀasꢀaꢀ
promisingꢀapproachꢀforꢀultra‐deepꢀdesulfurizationꢀunderꢀmildꢀ
reactionꢀ conditionsꢀ [2,15].ꢀ Inꢀ theꢀ CODSꢀ system,ꢀ sulfurꢀ com‐
poundsꢀinꢀtheꢀoilꢀphaseꢀareꢀadsorbedꢀbyꢀtheꢀcatalystꢀfirst,ꢀandꢀ
thenꢀ oxidizedꢀ toꢀ sulfonesꢀ inꢀ theꢀ presenceꢀ ofꢀ anꢀ oxidant.ꢀ Theꢀ
oxidationꢀ productꢀ isꢀ separatedꢀ byꢀ extraction,ꢀ distillation,ꢀ orꢀ
adsorptionꢀ[9,16,17].ꢀZhengꢀandꢀcoworkersꢀ[15]ꢀreportedꢀthatꢀaꢀ
catalystꢀ withꢀ titaniumꢀ dioxideꢀ improvedꢀ theꢀ desulfurizationꢀ
Withꢀ theꢀ rapidꢀ developmentꢀ ofꢀ globalꢀ industries,ꢀ theꢀ con‐
sumptionꢀofꢀfuelꢀoilꢀisꢀincreasingꢀaroundꢀtheꢀworld,ꢀwhichꢀhasꢀ
ledꢀtoꢀincreasingꢀtoxicꢀsubstanceꢀandꢀcarbonꢀemissions.ꢀCrudeꢀ
oil‐derivedꢀ fuelsꢀ containꢀ aꢀ complexꢀ rangeꢀ ofꢀ componentsꢀ in‐
cludingꢀ variousꢀ sulfurꢀ compounds.ꢀ Amongꢀ theseꢀ sulfurꢀ com‐
pounds,ꢀ organosulfurꢀ compoundsꢀ suchꢀ asꢀ benzothiopheneꢀ
(
(
BT),ꢀ dibenzothiopheneꢀ (DBT),ꢀ 4,6‐dimethyldibenzothiopheneꢀ
4,6‐DMDBT)ꢀandꢀtheirꢀderivativesꢀareꢀtheꢀmainꢀsourceꢀofꢀSO
x
ꢀ
whichꢀleadꢀtoꢀairꢀpollutionꢀandꢀacidꢀrainꢀ[1,2].ꢀSo,ꢀultra‐cleanꢀ
fuelꢀ productionꢀ isꢀ needed.ꢀ Manyꢀ methodsꢀ haveꢀ beenꢀ usedꢀ toꢀ
removeꢀsulfurꢀfromꢀfuels,ꢀsuchꢀasꢀbiodesulfurizationꢀ[3,4],ꢀse‐
lectiveꢀ adsorptionꢀ [5,6],ꢀ extractionꢀ byꢀ impregnantꢀ [7],ꢀ extrac‐
tion‐oxidationꢀ [8],ꢀ alkylationandꢀ [9],ꢀ hydrodesulfurizationꢀ
(HDS)ꢀandꢀoxidativeꢀdesulfurizationꢀ(ODS).ꢀHDSꢀisꢀhighlyꢀeffi‐
cientꢀinꢀremovingꢀthiols,ꢀsulfidesꢀandꢀdisulfidesꢀ[10].ꢀNonethe‐
*ꢀCorrespondingꢀauthor.ꢀTel:ꢀ+86‐27‐68862181;ꢀFax:ꢀ+86‐27‐68862181;ꢀE‐mail:ꢀwghwang@263.netꢀ ꢀ
ThisꢀworkꢀwasꢀsupportedꢀbyꢀtheꢀNationalꢀNaturalꢀScienceꢀFoundationꢀofꢀChinaꢀ(21473126).ꢀ
DOI:ꢀ10.1016/S1872‐2067(16)62558‐5ꢀ|ꢀhttp://www.sciencedirect.com/science/journal/18722067ꢀ|ꢀChin.ꢀJ.ꢀCatal.,ꢀVol.ꢀ37,ꢀNo.ꢀ12,ꢀDecemberꢀ2016ꢀ ꢀ

ꢀ
YongshengꢀTianꢀetꢀal.ꢀ/ꢀChineseꢀJournalꢀofꢀCatalysisꢀ37ꢀ(2016)ꢀ2098–2105ꢀ
2099ꢀ
efficiency,ꢀ andꢀ theꢀ desulfurizationꢀ productꢀ wasꢀ separatedꢀ byꢀ
extractionꢀ byꢀ anꢀ ionicꢀ liquid.ꢀ Toꢀ improveꢀ desulfurizationꢀ effi‐
ciency,ꢀresearchersꢀneedꢀtoꢀdevelopꢀsuitableꢀcatalysts.ꢀStudiesꢀ
onꢀtheꢀCODSꢀprocessꢀhaveꢀemployedꢀdifferentꢀcatalystsꢀsuchꢀasꢀ
zeolitesꢀ [18],ꢀ formicꢀ acidꢀ [19,20],ꢀ sodiumꢀ bicarbonateꢀ [21],ꢀ
activatedꢀ carbonꢀ [22],ꢀ andꢀ peroxidaseꢀ [23,24].ꢀ Amongꢀ these,ꢀ
Mo‐containingꢀcatalystsꢀshowedꢀgoodꢀperformanceꢀinꢀtheꢀCODSꢀ
systemꢀbecauseꢀofꢀtheꢀactiveꢀradicalꢀspeciesꢀproducedꢀbyꢀtheꢀ
Forꢀtheꢀpreparationꢀofꢀtheꢀcatalysts,ꢀ5.02ꢀmLꢀconcentratedꢀ
sulfuricꢀacidꢀandꢀ0.8891ꢀgꢀPVP‐k30ꢀwereꢀdispersedꢀinꢀ57ꢀmLꢀofꢀ
deionizedꢀ waterꢀ inꢀ aꢀ 200ꢀ mLꢀ conicalꢀ flaskꢀ underꢀ stirringꢀ atꢀ
roomꢀtemperature.ꢀTEOSꢀ(8.32ꢀg)ꢀwasꢀaddedꢀintoꢀtheꢀsolution.ꢀ
ThenꢀHPMoꢀwasꢀdropwiseꢀaddedꢀintoꢀtheꢀmixtureꢀsolutionꢀandꢀ
paleꢀ yellowꢀ flocksꢀ wereꢀ obtained.ꢀ Afterꢀ that,ꢀ theꢀ suspensionꢀ
wasꢀcontinuouslyꢀstirredꢀforꢀ1ꢀhꢀbeforeꢀagingꢀforꢀ4ꢀhꢀatꢀroomꢀ
temperature.ꢀSubsequentlyꢀtheꢀpowderꢀobtainedꢀwasꢀdriedꢀatꢀ
105ꢀ °Cꢀ inꢀ aꢀ vacuumꢀ oven.ꢀ Finally,ꢀ theꢀ resultingꢀ paleꢀyellowꢀ
powderꢀ wasꢀ calcinedꢀ atꢀ 420ꢀ °Cꢀ forꢀ 12ꢀ hꢀ andꢀ labeledꢀ asꢀ
interactionꢀbetweenꢀMo(VI)ꢀsitesꢀandꢀH
2
O ꢀandꢀtheyꢀhaveꢀbeenꢀ
2
widelyꢀinvestigatedꢀandꢀemployedꢀ[25–28].ꢀForꢀinstance,ꢀGar‐
cía‐Gutiérrezꢀandꢀcoworkersꢀ[27]ꢀreportedꢀthatꢀaꢀcatalystꢀwithꢀ
HPMo‐SiO
2
ꢀ(theꢀMo/SiO ꢀmassꢀratioꢀwasꢀ15.9%).ꢀ ꢀ
2
Moꢀasꢀtheꢀactiveꢀphaseꢀandꢀhydrogenꢀperoxideꢀ(H
2
O )ꢀasꢀoxi‐
2
dantꢀ inꢀ theꢀ oxidationꢀ reactionꢀ improvedꢀ theꢀ desulfurizationꢀ
efficiency.ꢀInꢀtheꢀprocessꢀofꢀoxidativeꢀdesulfurization,ꢀtheꢀcata‐
lystꢀ supportꢀ alsoꢀ playsꢀ anꢀ importantꢀ role.ꢀ Titaniumꢀ dioxideꢀ
2.3.ꢀ ꢀ Catalystꢀcharacterizationꢀ
–1
FT‐IRꢀ spectraꢀ (4000–500ꢀ cm )ꢀ wereꢀ recordedꢀ atꢀ roomꢀ
temperatureꢀonꢀaꢀBrukerꢀVERTEXꢀ70ꢀFT‐IRꢀspectrometerꢀusingꢀ
KBrꢀinꢀtheꢀratioꢀofꢀ1:200.ꢀTheꢀX‐rayꢀdiffractionꢀ(XRD)ꢀpatternsꢀ
wereꢀrecordedꢀonꢀaꢀPhillipsꢀXpertꢀProꢀpowderꢀdiffractionꢀsys‐
(
TiO )ꢀ[15],ꢀzeoliteꢀ[5],ꢀSBA‐15ꢀandꢀMCM‐4ꢀ[29]ꢀasꢀtheꢀcatalystꢀ
2
supportꢀ haveꢀ beenꢀ extensivelyꢀ investigated,ꢀ andꢀ manyꢀ re‐
searchersꢀ haveꢀ studiedꢀ theꢀ effectꢀ ofꢀ differentꢀ morphologies.ꢀ
Fromꢀtheꢀperspectiveꢀofꢀapplication,ꢀamorphousꢀSiO
2
ꢀhasꢀfoundꢀ
temꢀusingꢀCuꢀK ꢀradiationꢀwithꢀaꢀNiꢀfilterꢀoverꢀtheꢀrangeꢀ10°ꢀ≤ꢀ
α
31
wideꢀapplicationsꢀinꢀtheꢀfieldsꢀofꢀselectiveꢀseparationꢀandꢀca‐
talysisꢀ becauseꢀ ofꢀ itsꢀ highꢀ chemicalꢀ andꢀ thermalꢀ stabilities,ꢀ
largeꢀsurfaceꢀareaꢀandꢀgoodꢀcompatibilityꢀwithꢀotherꢀmaterials.ꢀ
AmorphousꢀSiO2ꢀisꢀalsoꢀeasyꢀtoꢀsynthesizeꢀandꢀaꢀcheapꢀmaterialꢀ
comparedꢀ toꢀ otherꢀ supportsꢀ [30].ꢀ Inꢀ addition,ꢀ theꢀ surfaceꢀ ofꢀ
2θꢀ≤ꢀ80°.ꢀSolid‐stateꢀ PꢀNMRꢀwasꢀrecordedꢀonꢀanꢀAgilentꢀDD2ꢀ
spectrometerꢀ (600ꢀ MHz).ꢀ Theꢀ X‐rayꢀ photoelectronꢀ spectrumꢀ
(XPS)ꢀ measurementsꢀ wereꢀ performedꢀ withꢀ aꢀ Multilabꢀ
2000X‐rayꢀ photoelectronꢀ spectrometerꢀ (VG,ꢀ UK).ꢀ Theꢀ poreꢀ
structureꢀofꢀtheꢀcatalystsꢀwasꢀobtainedꢀfromꢀnitrogenꢀadsorp‐
tionꢀisothermsꢀwhichꢀwereꢀmeasuredꢀatꢀ196ꢀ°Cꢀinꢀtheꢀrelativeꢀ
pressureꢀ rangeꢀ ofꢀ 0.001–1ꢀ withꢀ aꢀ Quantachromeꢀ instrumentꢀ
(Autosorb‐1‐C‐TCD‐MS).ꢀ ꢀ
amorphousꢀmesoporousꢀSiO
helpꢀtheꢀadsorptionꢀofꢀtheꢀoxidationꢀproductꢀ[31].ꢀUpꢀtoꢀnow,ꢀ
thereꢀareꢀfewꢀreportsꢀonꢀanꢀamorphousꢀSiO ꢀloadedꢀHPMoꢀasꢀ
theꢀcatalystꢀinꢀanꢀoxidativeꢀdesulfurizationꢀsystem.ꢀ
Inꢀthisꢀpaper,ꢀcatalystsꢀofꢀHPMo‐SiO ꢀwasꢀsynthesizedꢀandꢀ
2
ꢀisꢀrichꢀinꢀhydroxylꢀgroups,ꢀwhichꢀ
2
2
2.4.ꢀ ꢀ Catalyticꢀevaluationꢀ
appliedꢀ inꢀ theꢀ CODSꢀ system.ꢀ Theꢀ reactionꢀ conditions,ꢀ kineticꢀ
studyꢀofꢀtheꢀcatalyticꢀoxidationꢀandꢀreuseꢀofꢀtheꢀcatalystꢀwereꢀ
investigatedꢀ inꢀ theꢀ desulfurizationꢀ ofꢀ aꢀ modelꢀ oil.ꢀ Whenꢀ
Theꢀ oxidativeꢀ desulfurizationꢀ wasꢀ studiedꢀ byꢀ employingꢀ
modelꢀoilsꢀ containingꢀrefractoryꢀsulfurꢀ compoundsꢀ whichꢀ areꢀ
commonlyꢀfoundꢀinꢀfuels,ꢀlikeꢀDBTꢀorꢀBT.ꢀTheꢀmodelꢀfuelsꢀwereꢀ
preparedꢀ byꢀ dissolvingꢀ BTꢀ orꢀ DBTꢀ inꢀ n‐octaneꢀ toꢀ obtainꢀ theꢀ
solutionꢀ withꢀ aꢀ sulfurꢀ contentꢀ ofꢀ 400ꢀ mg/g.ꢀ Inꢀ theseꢀ experi‐
ments,ꢀ 10ꢀ mLꢀ ofꢀ theꢀ modelꢀ oilꢀ wasꢀ introducedꢀ intoꢀ aꢀ
three‐neckedꢀglassꢀreactorꢀequippedꢀwithꢀaꢀcondenser,ꢀstirrerꢀ
andꢀthermometer.ꢀTheꢀreactorꢀwasꢀplacedꢀinꢀaꢀwaterꢀbathꢀatꢀaꢀ
HPMo‐SiO ꢀ wasꢀ employedꢀ asꢀ theꢀ catalyst,ꢀ sulfurꢀ removalꢀ ofꢀ
2
DBTꢀ andꢀ BTꢀ approachedꢀ 100.0%ꢀ underꢀ mildꢀ reactionꢀ condi‐
tions.ꢀGC‐MSꢀandꢀmicrocoulometricꢀanalysisꢀwereꢀemployedꢀtoꢀ
investigateꢀtheꢀreactionꢀprogressꢀofꢀtheꢀCODSꢀsystem.ꢀDBTꢀre‐
movalꢀ couldꢀ stillꢀ reachꢀ 95.2%ꢀ (andꢀ 95.7%ꢀ forꢀ BT)ꢀ afterꢀ 10ꢀ
timesꢀ recycling.ꢀ Thisꢀ meansꢀ thatꢀ theꢀ HPMo‐SiO ꢀ catalystꢀ hasꢀ
2
highꢀ activityꢀ andꢀ stabilityꢀ inꢀ theꢀ CODSꢀ system.ꢀ Theꢀ catalystꢀ
preparedꢀinꢀthisꢀresearchꢀcanꢀcompletelyꢀadsorbꢀtheꢀoxidationꢀ
products,ꢀ andꢀ theꢀ furtherꢀ separationꢀ operationꢀ ofꢀ oxidationꢀ
productsꢀwasꢀnotꢀneeded.ꢀTheꢀCODSꢀsystemꢀintroducedꢀinꢀthisꢀ
paperꢀeffectivelyꢀimprovedꢀtheꢀeconomyꢀofꢀtheꢀdesulfurizationꢀ
processꢀandꢀreducedꢀtheꢀlossꢀofꢀfuels.ꢀ
constantꢀtemperatureꢀandꢀthenꢀHPMo‐SiO
2
ꢀwasꢀaddedꢀintoꢀtheꢀ
reactor.ꢀ Theꢀ reactionꢀ mixtureꢀ wasꢀ continuouslyꢀ stirredꢀ andꢀ
heatedꢀtoꢀtheꢀsetꢀtemperature.ꢀSubsequently,ꢀhydrogenꢀperox‐
ideꢀwasꢀaddedꢀtoꢀtheꢀreactionꢀmixture,ꢀandꢀthisꢀwasꢀrecordedꢀasꢀ
theꢀinitialꢀtimeꢀofꢀtheꢀreaction.ꢀAfterꢀtheꢀreaction,ꢀtheꢀmixtureꢀ
wasꢀ separatedꢀ byꢀ centrifugation.ꢀ Theꢀ reactionꢀ productsꢀ wereꢀ
thenꢀ analyzedꢀ onꢀ anꢀ HPꢀ 6890ꢀ gasꢀ chromatographꢀ equippedꢀ
withꢀanꢀHP‐5ꢀcapillaryꢀcolumnꢀandꢀanꢀFIDꢀdetector.ꢀ
2.ꢀ ꢀ Experimentalꢀ
2.1.ꢀ ꢀ Materialsꢀ
3.ꢀ ꢀ Resultsꢀandꢀdiscussionꢀ
Allꢀ materialsꢀ inꢀ thisꢀ experimentꢀ wereꢀ commercialꢀ reagentꢀ
3.1.ꢀ ꢀ Characterizationꢀofꢀcatalystsꢀ
grade.ꢀPolyvinylpyrrolidoneꢀ(PVP‐k30),ꢀn‐octane,ꢀconcentratedꢀ
sulfuricꢀ acid,ꢀ phosphomolybdicꢀ acidꢀ (HPMo),ꢀ tetraethylortho‐
silicateꢀ(TEOS),ꢀbenzothiopheneꢀ(BT),ꢀdibenzothiopheneꢀ(DBT),ꢀ
Fig.ꢀ 1ꢀ showsꢀ theꢀ FT‐IRꢀ spectraꢀ ofꢀ HPMo‐SiO
2
,ꢀ SiO ꢀ andꢀ
2
HPMo.ꢀTheꢀfourꢀFT‐IRꢀbandsꢀcharacteristicꢀofꢀHPMoꢀwithꢀtheꢀ
–1ꢀ
2 2
andꢀ 30ꢀwt%ꢀhydrogenꢀ peroxideꢀ(H O )ꢀwereꢀpurchasedꢀfromꢀ
Kegginꢀstructureꢀappearedꢀatꢀ1065ꢀcm (stretchingꢀfrequencyꢀ
–1
SinopharmꢀChemicalꢀReagentꢀCo.,ꢀLtd.ꢀ ꢀ
ofꢀP–OꢀinꢀtheꢀcenterꢀPO
4
ꢀtetrahedronꢀofꢀHPMo),ꢀ967ꢀcm ꢀ(ter‐
ꢀoctahedron),ꢀ871ꢀandꢀ
788ꢀcm ꢀ(Mo–O–Moꢀbands)ꢀ[32].ꢀOwingꢀtoꢀtheꢀoverlapꢀofꢀtheꢀ
minalꢀMo=OꢀbandsꢀinꢀtheꢀexteriorꢀMoO
6
–1
2.2.ꢀ ꢀ Catalystꢀpreparationꢀ

2100ꢀ
YongshengꢀTianꢀetꢀal.ꢀ/ꢀChineseꢀJournalꢀofꢀCatalysisꢀ37ꢀ(2016)ꢀ2098–2105ꢀ
HPMo-SiO
2
SiO
2
HPMo-SiO
2
HPMo
HPMo
9
2
000 1800 1600 1400 1200 1000 800 600 400
-9
-6
-3
0

3
6
1
Wavenumber (cm )
Fig.ꢀ1.ꢀFT‐IRꢀspectraꢀofꢀHPMo‐SiO ,ꢀSiO
Fig.ꢀ3. 31PꢀNMRꢀspectraꢀofꢀHPMo‐SiO
ꢀandꢀHPMo.ꢀ
2
2
ꢀandꢀHPMo.ꢀ
2
–1
adsorbedꢀbyꢀSiO ,ꢀwhileꢀanotherꢀpartꢀofꢀHPMoꢀwasꢀimmobilizedꢀ
7
88ꢀ cm ꢀ Mo–O–Moꢀ peakꢀ withꢀ thatꢀ ofꢀ theꢀ Si–O–Siꢀ stretchingꢀ
2
vibrationꢀofꢀtheꢀmesoporousꢀsupport,ꢀtheꢀbandsꢀcorrespondingꢀ
toꢀtheꢀKegginꢀstructureꢀofꢀHPMoꢀwereꢀweakenedꢀafterꢀtheꢀim‐
mobilizationꢀofꢀHPMoꢀonꢀtheꢀsupport.ꢀAsꢀtheꢀdetectionꢀofꢀtheꢀ
peaksꢀ onꢀ bulkꢀ HPMoꢀ revealed,ꢀ theꢀ Kegginꢀ structureꢀ wasꢀ re‐
tainedꢀafterꢀimmobilization.ꢀHowever,ꢀaꢀslightꢀshiftꢀoccurredꢀasꢀ
aꢀresultꢀofꢀHPMo’sꢀinteractionꢀwithꢀtheꢀfunctionalꢀgroupsꢀofꢀtheꢀ
support.ꢀ
onꢀtheꢀmesoporousꢀsilicaꢀskeletonꢀthroughꢀchemicalꢀbonds.ꢀTheꢀ
chemicalꢀ bondꢀ bindsꢀ HPMoꢀ andꢀ SiO ꢀ withꢀ aꢀ strongerꢀ force,ꢀ
2
whichꢀ significantlyꢀ reducedꢀ theꢀ desorptionꢀ ofꢀ theꢀ catalystsꢀ inꢀ
theꢀ processꢀ ofꢀ desulfurization.ꢀ Inꢀ addition,ꢀ 31Pꢀ NMRꢀ furtherꢀ
confirmedꢀ thatꢀ theꢀ integrityꢀ ofꢀ theꢀ Kegginꢀ structureꢀ wasꢀ
maintainedꢀafterꢀimmobilizationꢀonꢀtheꢀSiO ꢀsupports.ꢀ
2
Inꢀorderꢀtoꢀgetꢀfurtherꢀinformationꢀonꢀtheꢀchemicalꢀcompo‐
sitionꢀofꢀtheꢀcatalyst,ꢀXPSꢀwasꢀperformedꢀtoꢀexamineꢀtheꢀsur‐
faceꢀchemicalꢀ components.ꢀTheꢀresultsꢀ areꢀexhibitedꢀinꢀFig.ꢀ 4ꢀ
andꢀshowedꢀthatꢀtheꢀbindingꢀenergyꢀofꢀtheꢀMoꢀ3dꢀpeakꢀonꢀtheꢀ
catalystꢀsampleꢀwasꢀ232.8ꢀeV,ꢀindicatingꢀtheꢀpresenceꢀofꢀMoꢀinꢀ
theꢀ catalyst.ꢀ Fig.ꢀ 4(b)ꢀ presentsꢀ theꢀ Moꢀ 3dꢀ XPSꢀ spectrumꢀ ofꢀ
Fig.ꢀ2ꢀshowsꢀtheꢀpowderꢀXRDꢀpatternsꢀofꢀtheꢀcatalysts.ꢀAsꢀ
shownꢀinꢀFig.ꢀ2,ꢀtheꢀcharacteristicꢀpeaksꢀofꢀHPMoꢀatꢀ2θꢀ=ꢀ12.7°,ꢀ
2
3.3°,ꢀ25.7°,ꢀ29.7°,ꢀandꢀ38.9°ꢀemerged,ꢀwhichꢀbelongedꢀtoꢀtheꢀ
characteristicꢀ peaksꢀ ofꢀ theꢀ MoO3ꢀunitꢀ [33].ꢀ Theꢀ characteristicꢀ
peaksꢀ ofꢀ MoO ꢀ wereꢀ almostꢀ notꢀ detectedꢀ withꢀ HPMo‐SiO ,ꢀ
whichꢀindicatedꢀthatꢀtheꢀHPMoꢀclustersꢀwereꢀfinelyꢀdispersedꢀ
onꢀtheꢀsupportꢀofꢀSiO .ꢀ ꢀ ꢀ
3
2
HPMo‐SiO .ꢀSpectralꢀdeconvolutionꢀdemonstratedꢀtheꢀ appear‐
2
2
anceꢀofꢀtwoꢀsignalsꢀatꢀ232.8ꢀandꢀ235.8ꢀeVꢀforꢀMoꢀ3d5/2ꢀandꢀMoꢀ
31
Theꢀsolidꢀ PꢀNMRꢀspectraꢀofꢀtheꢀcatalystsꢀareꢀshownꢀinꢀFig.ꢀ
.ꢀTheꢀchemicalꢀshiftꢀofꢀPꢀisꢀmainlyꢀdeterminedꢀbyꢀtheꢀchemicalꢀ
3
environmentꢀ ofꢀ Pꢀ inꢀ theꢀ catalyst.ꢀ Forꢀ pureꢀ HPMo,ꢀ aꢀ singleꢀ
(a)
31
absorptionꢀpeakꢀappearedꢀatꢀδꢀ=ꢀ3.33.ꢀTheꢀ PꢀNMRꢀspectrumꢀ
ofꢀ HPMo‐SiO ꢀ presentedꢀ aꢀ broadꢀ resonanceꢀ centeredꢀ atꢀ δꢀ =ꢀ
3.36ꢀ[34]ꢀ(δꢀ=ꢀ3.33ꢀforꢀHPMo,ꢀwithꢀaꢀweakꢀshoulderꢀatꢀδꢀ=ꢀ
4.09).ꢀ Theꢀ shoulderꢀ peakꢀ canꢀ beꢀ attributedꢀ toꢀ theꢀ chemicalꢀ
ꢀ skeleton.ꢀ Theꢀ
40)–]ꢀ wasꢀ formedꢀ betweenꢀ
2


interactionꢀ betweenꢀ HPMoꢀ andꢀ theꢀ SiO
compoundꢀ ofꢀ [(≡SiOH
)+(H
2
Mo 3d
2
2
PMo12O
HPMoꢀ andꢀ theꢀ hydroxylꢀ groupsꢀ onꢀ theꢀ surfaceꢀ ofꢀ silicaꢀ [35].ꢀ
Therefore,ꢀitꢀcanꢀbeꢀ concludedꢀthatꢀ someꢀHPMoꢀwasꢀ physicalꢀ
1000
800
600
400
200
0
Binding energy (eV)
▼
MoO
3
▼
(b)
▼
▼
232.8
235.8
HPMo-SiO
2
▼
▼
▼
▼
▼
HPMo
▼
10
20
30
40
50
/(°)
Fig.ꢀ2.ꢀX‐rayꢀdiffractionsꢀofꢀHPMo‐SiO
60
70
80
2
42 240 238 236 234 232 230 228

Binding energy (eV)
2
ꢀandꢀHPMo.ꢀ
Fig.ꢀ4.ꢀXPSꢀspectraꢀofꢀHPMo‐SiO .ꢀ(a)ꢀSurvey;ꢀ(b)ꢀMoꢀ3d.ꢀ
2

ꢀ
YongshengꢀTianꢀetꢀal.ꢀ/ꢀChineseꢀJournalꢀofꢀCatalysisꢀ37ꢀ(2016)ꢀ2098–2105ꢀ
d3/2,ꢀ respectively,ꢀ andꢀ theseꢀ bindingꢀ energyꢀ valuesꢀ corre‐
2101ꢀ
3
6+
spondedꢀtoꢀMo .ꢀSomeꢀresearchersꢀhaveꢀassignedꢀtheꢀsignalꢀatꢀ
32.7ꢀeVꢀtoꢀtheꢀpolymolybdateꢀspeciesꢀinꢀtheꢀhighestꢀoxidationꢀ
stateꢀ[36].ꢀ
TheꢀadsorptionꢀisothermsꢀofꢀtheꢀcatalystsꢀareꢀshownꢀinꢀFig.ꢀ
.ꢀ Usingꢀ theꢀ IUPACꢀ classification,ꢀ theꢀ HPMo‐SiO ꢀ adsorptionlꢀ
100
2
8
6
4
2
0
0
0
0
DBT
5
2
isothermꢀwithꢀaꢀH4ꢀTypeꢀdesorptionꢀhysteresisꢀloopꢀisꢀaꢀTypeꢀ
IVꢀ isotherm,ꢀ whichꢀ isꢀ characteristicꢀ ofꢀ mesoporousꢀ materialsꢀ
[
NLDFTꢀ equilibriumꢀ model.ꢀ Theꢀ poreꢀ sizeꢀ distributionꢀ ofꢀ
HPMo‐SiO
BT
37].ꢀ Theꢀ adsorptionꢀ isothermꢀ dataꢀ wereꢀ processedꢀ byꢀ theꢀ
2
ꢀwasꢀconcentratedꢀatꢀtheꢀaverageꢀporeꢀdiameterꢀofꢀ
2.91ꢀ nm,ꢀ theꢀ specificꢀ surfaceꢀ areaꢀ wasꢀ 365.0ꢀ m /g,ꢀ andꢀ theꢀ
2
1
0
.0
0.2
0.4
Catalyst/model oil mass ratio (%)
Fig.ꢀ6.ꢀEffectꢀofꢀcatalyst/modelꢀoilꢀonꢀBTꢀandꢀDBTꢀremoval.ꢀConditionsꢀ
forꢀBTꢀremoval:ꢀV(H )/V(modelꢀoil)ꢀ=ꢀ0.3%,ꢀ60ꢀ°C,ꢀ30ꢀmin;ꢀConditionsꢀ
forꢀDBTꢀremoval:ꢀV(H )/V(oil)ꢀ=ꢀ0.3%,ꢀ55ꢀ°C,ꢀ15ꢀmin.ꢀ
0.6
0.8
1.0
1.2
3
totalꢀporeꢀvolumeꢀwasꢀ1.237ꢀcm /g.ꢀTheꢀabundantꢀporesꢀofꢀtheꢀ
structureꢀandꢀhighꢀporeꢀcontentꢀwouldꢀassistꢀtheꢀadsorptionꢀofꢀ
BTꢀandꢀDBTꢀonꢀtheꢀcatalystꢀsurfaceꢀandꢀtheꢀoxidationꢀreaction,ꢀ
whichꢀfurtherꢀimprovedꢀsulfurꢀremovalꢀfromꢀtheꢀfuelꢀoil.ꢀ ꢀ
2
O
2
O
2 2
3.2.ꢀ ꢀ Oxidativeꢀdesulfurizationꢀofꢀtheꢀmodelꢀfuelꢀoilꢀ
0.7%ꢀforꢀDBTꢀ(andꢀ1.0%ꢀforꢀBT),ꢀtheꢀremovalꢀrateꢀofꢀtheꢀsulfurꢀ
compoundꢀinꢀtheꢀmodelꢀoilꢀwasꢀ100.0%.ꢀ
3.2.1.ꢀ ꢀ Effectꢀofꢀmassꢀratioꢀofꢀcatalyst/modelꢀoilꢀ
Toꢀ verifyꢀ theꢀ CODSꢀ activity,ꢀ oxidativeꢀ desulfurizationꢀ ex‐
3
.2.2.ꢀ ꢀ EffectꢀofꢀvolumeꢀratioꢀofꢀH
TheꢀeffectꢀofꢀV(H )/V(modelꢀoil)ꢀonꢀDBTꢀandꢀBTꢀremovalꢀ
rateꢀofꢀmodelꢀoilꢀisꢀshownꢀinꢀFig.ꢀ7.ꢀWithꢀincreasingꢀH ,ꢀtheꢀ
removalꢀrateꢀofꢀDBTꢀandꢀBTꢀincreasedꢀfirstꢀandꢀthenꢀdecreased.ꢀ
WhenꢀV(H )/V(modelꢀoil)ꢀreachedꢀ0.3%,ꢀtheꢀremovalꢀratesꢀofꢀ
2
O
2
/modelꢀoilꢀ
perimentsꢀ ofꢀ DBTꢀ andꢀ BTꢀ wereꢀ performed.ꢀ Theꢀ effectꢀ ofꢀ
m(catalyst)/m(modelꢀ oil)ꢀ onꢀ DBTꢀ orꢀ BTꢀ removalꢀ rateꢀ ofꢀ theꢀ
modelꢀoilꢀwasꢀstudied.ꢀAsꢀshownꢀinꢀFig.ꢀ6,ꢀwithꢀtheꢀincreaseꢀofꢀ
O
2 2
O
2 2
HPMo‐SiO ,ꢀ theꢀ desulfurizationꢀ rateꢀ forꢀ bothꢀ DBTꢀ andꢀ BTꢀ
2
O
2 2
increasedꢀ gradually,ꢀ andꢀ theꢀ conversionꢀ ofꢀ DBTꢀ wasꢀ higherꢀ
thanꢀthatꢀofꢀBTꢀwithꢀtheꢀsameꢀamountꢀofꢀcatalyst.ꢀItꢀwasꢀalsoꢀ
observedꢀ thatꢀ whenꢀ theꢀ m(catalyst)/m(modelꢀ oil)ꢀ reachedꢀ
DBTꢀ andꢀ BTꢀ wereꢀ 100.0%.ꢀ Withꢀ theꢀ furtherꢀ increaseꢀ ofꢀ
hydrogenꢀ peroxide,ꢀ theꢀ desulfurizationꢀ efficiencyꢀ decreased.ꢀ
Theꢀdeclineꢀofꢀsulfurꢀremovalꢀrateꢀwasꢀprobablyꢀcausedꢀbyꢀthatꢀ
excessꢀ H
producedꢀH
centerꢀ andꢀ increasedꢀ theꢀ consumptionꢀ ofꢀ H
more,ꢀaꢀpartꢀofꢀtheꢀhydrophilicꢀcatalystꢀwasꢀtransferedꢀtoꢀtheꢀ
waterꢀ phaseꢀ whichꢀ reducedꢀ theꢀ catalystꢀ dispersedꢀ inꢀ theꢀ oil,ꢀ
whichꢀledꢀtoꢀtheꢀreductionꢀofꢀtheꢀdesulfurizationꢀrate.ꢀ
2
O
2
ꢀ causedꢀ aꢀ sideꢀ reactionꢀ catalyzedꢀ byꢀ Moꢀ thatꢀ
OꢀandꢀO ,ꢀandꢀtheꢀsideꢀreactionꢀoccupiedꢀtheꢀactiveꢀ
ꢀ [33].ꢀ Further‐
35
30
25
20
15
10
5
(a)
2
2
O
2 2
Des
Ads
3.2.3.ꢀ ꢀ Effectꢀofꢀtemperatureꢀ
Fig.ꢀ8ꢀshowsꢀtheꢀconversionꢀofꢀBTꢀandꢀDBTꢀcatalyzedꢀwithꢀ
2
HPMo‐SiO ꢀduringꢀtheꢀCODSꢀprocessꢀatꢀdifferentꢀtemperatures.ꢀ
TheꢀresultsꢀindicatedꢀthatꢀtheꢀconversionꢀofꢀDBTꢀcatalyzedꢀwithꢀ
0.0
0.2
0.4
0.6
0.8
1.0
Relative pressure (p/p
0
)
100
(b)
0.015
0.010
0.005
0.000
90
80
70
60
DBT
BT
0.1
0.2
0.3
0.4
0.5
0
15
30
45
60
75
2 2
H O /model oil volume ratio (%)
Pore size (nm)
Fig.ꢀ7.ꢀEffectꢀofꢀ hydrogenꢀ peroxideꢀcontentꢀonꢀ BTꢀandꢀDBTꢀ removal.
ConditionsꢀforꢀBTꢀremoval:ꢀm(catalyst)/m(oil)ꢀ=ꢀ0.7%,ꢀ60ꢀ°C,ꢀ30ꢀmin;ꢀ
ConditionsꢀforꢀDBTꢀremoval:ꢀm(catalyst)/m(oil)ꢀ=ꢀ0.4%,ꢀ55ꢀ°C,ꢀ15ꢀmin.
Fig.ꢀ 5.ꢀ Poreꢀ structureꢀ parametersꢀ ofꢀ HPMo‐SiO .ꢀ (a)ꢀ Adsorptionꢀ
isotherm;ꢀ(b)ꢀPoreꢀsizeꢀdistribution.ꢀ
2

2102ꢀ
YongshengꢀTianꢀetꢀal.ꢀ/ꢀChineseꢀJournalꢀofꢀCatalysisꢀ37ꢀ(2016)ꢀ2098–2105ꢀ
3
3
2
2
1
.5
.0
.5
.0
.5
(a)
1
00
E
a
(BT) = 40.5 kJ/mol
8
6
4
2
0
0
0
0
0
BT
a
E (DBT) = 30.6 kJ/mol
4
5
6
0 C
0 C
0 C
DBT
1.0
2
.95
3.00
3.05
3.10
10 /T (K )
3.15
3.20
3.25
0
10
20
30
40
3
-1
Reaction time (min)
Fig.ꢀ9.ꢀArrheniusꢀactivationꢀenergiesꢀforꢀDBTꢀandꢀBTꢀoxidation.ꢀ
(b)
100
(30.6ꢀkJ/mol)ꢀwasꢀlowerꢀthanꢀthatꢀofꢀtheꢀBTꢀoxidationꢀreactionꢀ
8
6
4
2
0
0
0
0
0
(40.5ꢀ kJ/mol),ꢀ whichꢀ showedꢀ thatꢀ DBTꢀ wasꢀ easierꢀ toꢀ oxidizeꢀ
thanꢀ BT.ꢀ Qiuꢀ andꢀ coworkersꢀ [33]ꢀ reportedꢀ thatꢀ theꢀ apparentꢀ
activationꢀenergyꢀofꢀDBTꢀinꢀtheꢀHPMo/SiO
temꢀwasꢀ33.0ꢀkJ/mol.ꢀTheꢀresultsꢀindicatedꢀthatꢀtheꢀmesopo‐
rousꢀ HPMo‐SiO ‐H ꢀ catalyticꢀ systemꢀ inꢀ theꢀ presentꢀ workꢀ
displayedꢀaꢀhigherꢀcatalyticꢀactivityꢀforꢀDBTꢀoxidation.ꢀ
2 2 2
‐H O ꢀcatalyticꢀsys‐
2
O
2 2
4
5
5
5 C
0 C
5 C
3.2.5.ꢀ ꢀ Reuseꢀcyclesꢀofꢀtheꢀcatalystsꢀ
TheꢀrelationshipꢀbetweenꢀDBTꢀandꢀBTꢀremovalꢀrateꢀinꢀtheꢀ
0
2
4
6
8
10 12 14 16 18 20
Reaction time (min)
CODSꢀreactionsꢀandꢀtheꢀutilizationꢀcyclesꢀisꢀshownꢀinꢀFig.ꢀ10.ꢀ
AfterꢀtheꢀCODSꢀreactions,ꢀtheꢀmixtureꢀofꢀHPMo‐SiO ꢀandꢀmodelꢀ
Fig.ꢀ8.ꢀEffectꢀofꢀreactionꢀtimeꢀonꢀBTꢀandꢀDBTꢀremoval.ꢀ(a)ꢀBT;ꢀ(b)ꢀDBT.ꢀ
ConditionsꢀforꢀBTꢀremoval:ꢀm(catalyst)/m(oil)ꢀ=ꢀ1.0%,ꢀV(H )/V(oil)ꢀ=ꢀ
.3%;ꢀ Conditionsꢀ forꢀ DBTꢀ removal:ꢀ m(catalyst)/m(oil)ꢀ =ꢀ 0.7%,ꢀ
V(H )/V(modelꢀoil)ꢀ=ꢀ0.3%.ꢀ
2
2
O
2
fuelꢀ oilꢀ wasꢀ separatedꢀ byꢀ centrifugation.ꢀ Theꢀ filterꢀ wasꢀ thenꢀ
driedꢀatꢀ105ꢀ°Cꢀinꢀaꢀvacuumꢀovenꢀforꢀ12ꢀh.ꢀAfterꢀtheꢀregenera‐
0
O
2 2
(a)
100
HPMo‐SiO ꢀwasꢀhigherꢀthanꢀthatꢀofꢀBTꢀunderꢀtheꢀsameꢀcondi‐
2
tions.ꢀThisꢀwasꢀbecauseꢀofꢀtheꢀhigherꢀelectronꢀdensityꢀonꢀtheꢀ
sulfurꢀatomꢀinꢀDBT.ꢀTheꢀelectronꢀdensityꢀonꢀtheꢀsulfurꢀatomsꢀisꢀ
80
60
40
20
0
5.758ꢀforꢀDBTꢀandꢀ5.739ꢀforꢀBT,ꢀwhichꢀwasꢀcalculatedꢀbyꢀOtsukiꢀ
etꢀal.ꢀ[38].ꢀTheꢀcatalystsꢀgaveꢀsignificantlyꢀhigherꢀCODSꢀactivityꢀ
withꢀtheꢀincreaseꢀofꢀreactionꢀtemperatureꢀbecauseꢀtheꢀformedꢀ
quantityꢀofꢀmetallicꢀperoxideꢀwasꢀincreasedꢀbyꢀtheꢀhigherꢀreac‐
tionꢀtemperatureꢀ[33].ꢀ ꢀ
1
2
3
4
5
6
7
8
9
10
(
3.2.4.ꢀ ꢀ Apparentꢀactivationꢀenergyꢀandꢀreactionꢀrateꢀconstantꢀ
Reuse times
Fromꢀ theꢀ reactionꢀ ratesꢀ determinedꢀ atꢀ differentꢀ tempera‐
b)
1
00
turesꢀ(Tableꢀ1),ꢀtheꢀapparentꢀactivationꢀenergiesꢀforꢀtheꢀCODSꢀ
reactionsꢀ (Fig.ꢀ 9)ꢀ wereꢀ calculatedꢀ byꢀ theꢀ Arrheniusꢀ equation.ꢀ
TheꢀCODSꢀreactionsꢀfittedꢀpseudo‐firstꢀorderꢀreactionꢀkinetics.ꢀ
TheꢀapparentꢀactivationꢀenergyꢀofꢀtheꢀDBTꢀoxidationꢀreactionꢀ
8
6
4
0
0
0
Tableꢀ1ꢀ
2
Reactionꢀ rateꢀconstantꢀ(k)ꢀandꢀ correlationꢀcoefficientꢀ(R )ꢀ forꢀ BTꢀ andꢀ
20
0
DBTꢀatꢀdifferentꢀtemperatures.ꢀ
–1
2
Sampleꢀ
BTꢀ ꢀ
BTꢀ
tꢀ(°C)ꢀ
40ꢀ
50ꢀ
60ꢀ
45ꢀ
kꢀ(min )ꢀ
0.043ꢀ
0.083ꢀ
0.109ꢀ
0.194ꢀ
0.239ꢀ
0.276ꢀ
R ꢀ
1
2
3
4
5
6
7
8
9
10
0.980ꢀ
0.993ꢀ
0.991ꢀ
0.994ꢀ
0.992ꢀ
0.995ꢀ
Reuse times
Fig.ꢀ10.ꢀEffectꢀofꢀreuseꢀtimesꢀonꢀtheꢀoxidativeꢀdesulfurizationꢀrateꢀofꢀBTꢀ
andꢀ DBT.ꢀ (a)ꢀ BT;ꢀ (b)ꢀ DBT.ꢀ Conditionsꢀ forꢀ BTꢀ removal:ꢀ m(catalyst)/
BTꢀ
DBTꢀ
DBTꢀ
DBTꢀ
m(oil)ꢀ=ꢀ1.0%,ꢀV(H
removal:ꢀm(catalyst)/m(oil)ꢀ=ꢀ0.7%,ꢀV(H
min.ꢀ
2
O
2
)/V(oil)ꢀ=ꢀ0.3%,ꢀ60ꢀ°C,ꢀ30ꢀmin;ꢀConditionsꢀforꢀDBTꢀ
50ꢀ
55ꢀ
2
O
2
)/V(oil)ꢀ=ꢀ0.3%,ꢀ55ꢀ°C,ꢀ10ꢀ

ꢀ
YongshengꢀTianꢀetꢀal.ꢀ/ꢀChineseꢀJournalꢀofꢀCatalysisꢀ37ꢀ(2016)ꢀ2098–2105ꢀ
2103ꢀ
tionꢀwasꢀcompleted,ꢀtheꢀHPMo‐SiO
elꢀoilꢀandꢀusedꢀforꢀaꢀsecondꢀCODSꢀreactionꢀcycle.ꢀ ꢀ
TheꢀMoꢀcontentꢀinꢀtheꢀcatalystꢀbeforeꢀandꢀafterꢀtheꢀoxidationꢀ
reactionꢀwasꢀdetectedꢀbyꢀICP‐AES,ꢀandꢀweakꢀleachingꢀofꢀHPMoꢀ
fromꢀtheꢀcatalystꢀwasꢀseenꢀinꢀtheꢀdesulfurizationꢀprocessꢀ(massꢀ
2
ꢀwasꢀmixedꢀwithꢀfreshꢀmod‐
micro‐coulometricꢀanalysis,ꢀaꢀreactionꢀprocessꢀcanꢀbeꢀproposedꢀ
asꢀtheꢀfollowing.ꢀTheꢀcatalyst,ꢀmodelꢀoilꢀandꢀhydrogenꢀperoxideꢀ
formedꢀaꢀheterogeneousꢀcatalysisꢀsystem.ꢀDuringꢀtheꢀreactionꢀ
process,ꢀBTꢀorꢀDBTꢀwasꢀfirstꢀadsorbedꢀonꢀtheꢀcatalyst,ꢀandꢀthenꢀ
oxidizedꢀbyꢀH
2
O ꢀ[15].ꢀTheꢀoxidationꢀproductꢀofꢀBTꢀwasꢀBTO2ꢀ
2
ratioꢀofꢀMo/SiO
times).ꢀItꢀisꢀdifficultꢀtoꢀremoveꢀBTO
2
ꢀdecreasedꢀfromꢀ15.9%ꢀtoꢀ14.8%ꢀafterꢀreuseꢀ10ꢀ
(DBTO2ꢀforꢀDBT),ꢀwhichꢀremainedꢀonꢀtheꢀsolidꢀcatalystꢀbecauseꢀ
ofꢀ itsꢀ highlyꢀ polarꢀ nature.ꢀ Asꢀ theꢀ BTꢀ orꢀ DBTꢀ wasꢀ transferredꢀ
2
ꢀandꢀDBTO ꢀbyꢀdirectꢀdry‐
2
ingꢀatꢀ105ꢀ°Cꢀbecauseꢀofꢀtheirꢀhighꢀmeltingꢀpointsꢀandꢀboilingꢀ
points,ꢀ whichꢀ ledꢀ toꢀ aꢀ slightꢀ decreaseꢀ inꢀ theꢀ desulfurizationꢀ
activityꢀafterꢀrepeatedꢀuseꢀofꢀtheꢀcatalyst.ꢀ
fromꢀ theꢀ oilꢀ phaseꢀ toꢀ theꢀ catalystꢀ andꢀ oxidizedꢀ toꢀ BTO
2
ꢀ orꢀ
DBTO ꢀcontinuously,ꢀaꢀlowꢀsulfurꢀmodelꢀoilꢀwasꢀachieved.ꢀ
2
4.ꢀ ꢀ Conclusionsꢀ
3.2.6.ꢀ ꢀ Analysisꢀofꢀoxidationꢀproductsꢀ
TheꢀSꢀcontentꢀofꢀtheꢀmodelꢀoilꢀdecreasedꢀfromꢀ400.0ꢀmg/gꢀ
AnꢀamorphousꢀHPMo‐SiO ꢀwhichꢀkeptꢀtheꢀKegginꢀstructureꢀ
2
toꢀ0.0ꢀmg/gꢀwithꢀ100.0%ꢀsulfurꢀremovalꢀrateꢀandꢀ99.2%ꢀmodelꢀ
oilꢀ recoveryꢀ inꢀ theꢀ reaction.ꢀ Inꢀ orderꢀ toꢀ analyzeꢀ theꢀ reactionꢀ
process,ꢀGC‐MSꢀanalysisꢀwasꢀadoptedꢀtoꢀresearchꢀtheꢀBTꢀandꢀ
DBTꢀreactionꢀprocess.ꢀAfterꢀtheꢀreaction,ꢀtheꢀoilꢀphaseꢀwasꢀsep‐
aratedꢀbyꢀcentrifugationꢀandꢀtheꢀsolidꢀcatalystꢀwasꢀextractedꢀbyꢀ
methanol.ꢀSubsequently,ꢀtheꢀoilꢀphaseꢀandꢀtheꢀmethanolꢀphaseꢀ
wereꢀanalyzedꢀbyꢀGC‐MS.ꢀAsꢀshownꢀinꢀFig.ꢀ11,ꢀonlyꢀtheꢀpeakꢀofꢀ
ofꢀ HPMoꢀwasꢀ preparedꢀ andꢀ appliedꢀinꢀtheꢀCODSꢀ system.ꢀTheꢀ
synthesisꢀofꢀtheꢀcatalystꢀwasꢀsimpleꢀandꢀeconomical.ꢀTheꢀcata‐
lystꢀgaveꢀhighꢀdesulfurizationꢀactivityꢀinꢀtheꢀremovalꢀofꢀBTꢀandꢀ
DBTꢀunderꢀmildꢀconditions.ꢀTheꢀcatalyticꢀoxidativeꢀactivityꢀforꢀ
DBTꢀwasꢀhigherꢀthanꢀthatꢀforꢀBTꢀunderꢀtheꢀsameꢀreactionꢀcon‐
ditions.ꢀTheꢀconversionꢀofꢀBTꢀandꢀDBTꢀincreasedꢀwithꢀtheꢀin‐
creaseꢀofꢀreactionꢀtemperature.ꢀTheꢀapparentꢀactivationꢀenergyꢀ
benzothiopheneꢀ sulfoneꢀ (BTO
dibenzothiopheneꢀ sulfoneꢀ (DBTO
wasꢀfoundꢀinꢀtheꢀmethanolꢀphase.ꢀHowever,ꢀnoꢀpeaksꢀbelongingꢀ
toꢀ BT,ꢀ DBT,ꢀ BTO ꢀ orꢀ DBTO ꢀ wereꢀ detectedꢀ inꢀ theꢀ oilꢀ phase,ꢀ
whichꢀ impliedꢀ thatꢀ thereꢀ wasꢀ enoughꢀ oxidantꢀ toꢀ oxidizeꢀ theꢀ
DBTꢀtoꢀDBTO ꢀinꢀ10ꢀminꢀ(BTꢀtoꢀBTO ꢀinꢀ30ꢀmin).ꢀMeanwhile,ꢀnoꢀ
2
,ꢀ Fig.ꢀ 11(a))ꢀ (m/zꢀ =ꢀ 166.1)ꢀ orꢀ
ofꢀ theꢀ DBTꢀ oxidationꢀ reactionꢀ catalyzedꢀ byꢀ HPMo‐SiO
lowerꢀthanꢀthatꢀofꢀBT.ꢀGC‐MSꢀandꢀmicro‐coulometricꢀanalysisꢀ
demonstratedꢀthatꢀBTO ꢀandꢀDBTO ꢀ adsorbedꢀ byꢀtheꢀcatalystꢀ
wereꢀtheꢀonlyꢀproductsꢀofꢀBTꢀandꢀDBTꢀoxidation.ꢀTheꢀrecyclingꢀ
experimentsꢀofꢀHPMo‐SiO ꢀindicatedꢀthatꢀDBTꢀandꢀBTꢀremovalꢀ
2
ꢀ wasꢀ
2
,ꢀ Fig.ꢀ 11(b))ꢀ (m/zꢀ =ꢀ 216.0)ꢀ
2
2
2
2
2
2
2
stillꢀreachedꢀ95.2%ꢀandꢀ95.7%ꢀafterꢀ10ꢀcycles.ꢀ
sulfurꢀ compoundꢀ wasꢀ detectedꢀ inꢀ theꢀ oilꢀ phaseꢀ byꢀ theꢀ mi‐
cro‐coulometricꢀ method.ꢀ Basedꢀ onꢀ theꢀ resultsꢀ ofꢀ GC‐MSꢀ andꢀ
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