学科分类
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48 个结果
  • 简介:SmallX-rayScattering(SAXS)experimentusingSynchrotronRadiationasX-raysourcewasusedtodeterminetheaveragewallthicknessofmesoporoussilicaprepardbycondensationoftetraethylorthosilicate(TEOS)usingnon-ionicalkylpolyethyleneoxide(AEO9)surfactantastemplates.Theresultsagreedwiththatofhigh-resolutionTEM(HRTEM)measurement.

  • 标签: 小角X射线散射分析 SAXS 中孔硅石 平均壁厚 结构分析
  • 简介:FollowingthebreakthroughinthetechnologyfordevelopmentandapplicationofmesoporouszeolitedevelopedbyPetroChina’sResearchInstituteofPetrochemicalIndustry(RIPI),thesaidmesoporouszeolitehasbeensuccessfullyappliedinthe1.2Mt/aRFCCunitattheLanzhouPetrochemicalCompany.

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  • 简介:Asmall-anglex-rayscattering(SAXS)techniqueusingsynchrotronradiationasthex-raysourcehasbeenemployedtocharacterizethemicrostructureofmesoporoussilicapreparedbyone-pottemplate-directedsynthesismethodology.ThescatteringofpuresilicaagreedwithPorod’slaw.thescatteringoforganomodifiedmesoporoussilicashowedanegativedeviationfromPorod’slaw,suggestingthataninterfaciallayerexistsbetweentheporesandsilicamatrix.Itwastheorganicgroupscomprisingtheinterface,asshownby^29Sicross-polarizationmagic-anglespinningnuclearmagneticresonanceimaging(^29SicpMAS/NMR)andFouriertransforminfraredspectroscopy(FTIR),thatcausedthisnegativedeviationofSAXSintensityfromPorod’slaw,andtheaveragethichnessoftheinterfaciallayercouldbededucedfromthisnegativedeviation.Copyright2001johnWileyandSons,Ltd.

  • 标签: SAXS 小角X射线散射分析 有机中孔硅石 结构分析 界面 负偏差
  • 简介:在这份报纸,包含四羧化物的anionic表面活化剂的一种新类型被四步的合成反应包括bromination反应和主要酰胺综合保护的反应。中介和在整个合成过程的每步的最后的产品被1HNMR和MS描绘。anionic表面活化剂的纯化通过再结晶和硅石胶化列层析的联合被完成。结构和在不同温度的这表面活化剂的批评micelle集中(CMC)也被调查。对容易的不同传统的monocarboxylate表面活化剂形成薄片状的mesostructure,这表面活化剂有六角形的mesophase结构和比较地低的CMC,希望在mesoporous金属氧化物的准备被使用。

  • 标签: 阴离子表面活性剂 介孔材料 羧酸盐 制备 临界胶束浓度 介孔结构
  • 简介:SmallangleX-rayscatteringexperimentshavebeenperformedtostudythemicrostructureofmessoporoussilicameterialspreparedbycondensationoftetraethylorthosilicateusingnonionicalkylpolyethyleneoxide(AEO9)andioniccetyltrimethylammoniumbromide(CTAB)surfactantastemplates.Itistheporeswithinthenanometrerangethatproducethemaincattering.ThescatteringofthepuresilicasystemsobeyPorod’slaw.Thismaybebecausethetemplatesproducesomeadditionalscatteringbackgroundandthenmakethescatteringofporesdistorted.TheresultsshowthatthefullremovaloftemplatesfromtheporesofthematerialsbySoxhletextractionisveryeasyforAEO9,butitisdifficultforCTAB.Thepositivedeviationcorrectionisalsoperfromed.

  • 标签: 小角X射线散射分析 SAXS 中孔硅石 结构分析 样品
  • 简介:Phosphorylatedmesoporouscarbons(PMCs)wereinvestigatedascatalystsinthedehydrationoffructosetohydroxymethylfurfural(HMF).TheacidicPMCsshowbetterselectivitytoHMFcomparedtosulfonatedcarboncatalyst(SC)despiteloweractivity.TheconcentrationofP-OgroupsonthePMCwascorrelatedwiththeactivity/selectivityofthecatalysts;thehighertheP-Oconcentration,thehighertheactivity.However,thehighertheP-Ocontent,thelowertheselectivitytoHMF.Indeed,alowerconcentrationoftheP-OgroupsminimizedthedegradationofHMFtolevulinicacidandtheformationofby-products,suchashumines.Stabilitytestsshowedthatthesesystemsdeactivateduetotheformationofhuminesandwaterinsolubleby-productsderivedfromthedehydrationoffructosewhichblockedthecatalyticallyactivesites.

  • 标签: 羟甲基糠醛 催化剂 磷酸化 脱水 果糖 介孔
  • 简介:Several2.0wt%nickelcatalystssupportedonnanometerbimodalmesoporousaluminosilicate(NBMAS),AlHMSandAlMCM-41werepreparedbymeansofthewetnessimpregnationmethod.ThecharacterizationtechniquessuchasPy-FTIRandH2chemisorptionshowedthattheamountofBronstedacidsitesdecreasedintheorderofNi/A1HMS>Ni/AlMCM-41>Ni/NBMAS,whilethenickeldispersiondifferedalittle.Inthecatalyticn-dodecanehydroconversion,thehighestconversionwasobtainedoverNi/NBMAS,andthelowestisomerizationselectivityoccurredoverNi/A1HMS.Forthecrackedproducts,thesymmetricalcarbonnumberdistributioncenteredatC6wasobtainedontheNi/AlMCM-41catalystduetothewellbalancedmetal/acidfunctions,whereastheNi/AlHMSandNi/NBMAScatalystsledtomoreC3-C5andC1+C11products,respectively.

  • 标签: n-十二烷 加氢转化作用 镍催化剂 中孔硅酸铝 双相催化剂
  • 简介:AseriesofxNiAl2O4/γ-Al2O3compositeswithvariousNicontentshavebeenpreparedviaone-steppartialhydrolysisofmetalnitratesaltsintheabsenceofsurfactantsandusedforcarbondioxidereformingofmethane.ThecharacterizationresultsdemonstratedthattheNiAl2O4/γ-Al2O3materialspossessedmesoporousstructuresofuniformporesizes;andtheNi2+ionswerecompletelyreactedwithaluminatoNiAl2O4spinelinthematricesusingN2sorption,XRD,TEM,andXPS.TheNiAl2O4/γ-Al2O3materialsexhibitedexcellentcatalyticpropertiesandsuperiorlong-termstabilityforcarbondioxidereformingofmethane.TheeffectsofNicontentontheintrinsicactivitiesandtheamountsofcokedispositionofthexNiAl2O4/γ-Al2O3catalystswerediscussedindetailforthecarbondioxidereformingofmethane.TheresultsrevealedthattheNiparticlesizesdidnotaffecttheintrinsicactivityofmetallicNi,butsmallerNiparticlescouldreducetherateofcokedeposition.

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  • 简介:Mesoporoustitania(meso-TiO2)由于它的万用的潜在的应用收到了广泛的注意。这份报纸用peroxo为meso-TiO2的制造报导一条低温度的templating途径巨人的酸(PTA)大音阶的第五音作为先锋和PluronicP123作为nonionic模板。TGA,XRD,N2吸着,FE-SEM和HRTEM被用来描绘获得的样品。结果与高表面区域显示出那meso-TiO2直到163m2汣獥??坍乃吗??

  • 标签: 介孔TIO2 光催化活性 表征 介孔材料 合成 介孔二氧化钛
  • 简介:ChiralmesoporoussilicaribbonsandrodswithinversedhandednesshavebeensynthesizedwiththesameenantiopureN-acylaminoacidattemperaturesof0℃and20℃,respectively.WithinvolvingCu^2+andmeso-tetra(4-sulfonatophenyl)porphyrin(TPPS)asprobes,ribbonsandrodsrevealedoppositesignalsindiffuse-reflectancecirculardichroism(DRCD)spectra,indicatingtheexistenceofinversedsupramolecularchiralimprintingsthroughhelicalstackingofamphiphiles.Thestructuralevolutionwassystematicallystudiedbythefreeze-driedproductssampledatdifferenttimeaftertheadditionofsilicaprecursors.TheH-bonding-dependedmolecularorientationprobablycontrolsthechiralsenseuponformingchiralmolecularstacking,whichwouldbetheoriginofsuchhandednessinversionphenomenon.

  • 标签: CHIRALITY HANDEDNESS INVERSION Circular DICHROISM Mesoporous
  • 简介:Byutilizinghardtemplatemethodtoadjustthemesoporelength,andalkaliactivationtogeneratemicropores,twohierarchicalporouscarbons(HPCs)wereprepared.Withcontrollingoftheirmesoporelengthandtheactivationconditions,thecomplexsystemcomposedbyHPCsandelectrolytewassimplifiedandtheeffectofmesoporelengthontheperformanceofHPCsaselectrodesinsupercapacitorswasinvestigated.Itisfoundthatwiththemesoporelengthgettingsmaller,theorderedareagetssmallerandthaggregationoccurs,whichiscausedbythehighsurfaceenergyofsmallgrains.HPCwithlongpore(HPCL)exhibitsadonut-likemorphologywithwell-definedorderedmesoporesandaregularorientationwhileinHPCwithshortpores(HPCS),shortmesoporesareonlyorderlydistributedinsmallregionsLongerorderedchannelsformunobstructedwaysforionstransportintheparticleswhileshorterchannels,onlyorderlydistributedinsmallareas,resultsinblockedpaths,whichmayhindertheelectrolytionstransport.Duetotheunobstructedstructure,HPCLexhibitsgoodratecapabilitywithacapacitancretentionrateover86%ascurrentdensityincreasingfrom50mA/gto1000mA/g.ThespecificcapacitanceofHPCLderivedfromthecyclicvoltammetrytestat10mV/sisupto201.72F/g,whilethespecificapacitanceofHPCSisonly193.65F/g.

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  • 简介:ThepreparationofhybridmesoporousMCM-48graftedbyvinylgroupviapost-graftingprocesswasreportedandstudiedbyX-raydiffraction,BETand29SisolidMASNMR.Anorganicβ-diketonateEuropiumcomplexthecorrespondingluminescencepropertywascharacterized.

  • 标签: MESOPOROUS HYBRID materials RARE earths
  • 简介:Byusingthebimodalmesoporoussilica(BMMS)asthecarrierandbutyltitanateasthetitaniumsource,theTiO2/BMMScatalystwasprepared.ThesampleswerecharacterizedbyXRD,XRF,N2adsorptionanddesorption,FTIR,UVvis,SEM,EDS,andTEMtechniques.ThetestresultsshowedthatTiO2wasamorphous,theTiO2/BMMScatalysthadanorderedbimodalmesoporousstructure,andthechemicalinteractionexistedbetweenBMMSandTiO2.SincetheTiO2/BMMShadalowerbandgap,itsphotocatalyticactivitywasbetterthanTiO2.UnderUVirradiationaone-potPODSsystemwassetup,usingTiO2/BMMSasthecatalyst,H2O2astheoxidant,andmethanolasthesolvent.TheTiO2/BMMScatalystshowedbetterphotocatalyticactivitythanthemono-modalmesoporousTiO2/SBA-15catalyst,andthedesulfurizationrateofdibenzothiophene(DBT)overTiO2/BMMScatalystcouldreach99.2%.TheTiO2/BMMScatalystalsohadsogoodstabilitythatthedesulfurizationrateofDBTdidnotdropapparentlyafter8cyclesofreusing,andcouldstillbecloseto90%.

  • 标签: BIMODAL MESOPOROUS silica amorphous TIO2 PHOTOCATALYTIC
  • 简介:Zr-Incorporatedmesoporoustitaniamaterialswerepreparedvianonsurfactanttemplatedsol-gelprocessofzirconium(IV)butoxide(ZBT)andtitanium(IV)butoxide(TBT)inthepresenceofureamoleculesastemplateorporeformingagent.TheeffcetsoftemplatecontentsontheporeparametersofthematerialssynthesizedwithfixedZrincorporationcontentswereinvestigatedbymitrogenadsorption-desrptionmeasurements,powderX-raydiffraction(XRD)studyandtransmissionelectronmicroscopy(TEM).ThechangesoftemplatecontentsplaysignificantrolesontheporeparametersatlowincorporsationcontentofZr.Theporediametersdisplayaclearincreasetendencywiththeincreaseoftemplatecontents.WhenhighZrincorporationcontentisused,thetemplatecontentshavelesseffectontheporediametersthatalmostkeepunchangedwiththeincreaseoftemplatecontents.AllthematerialspossesstypeIVisothermswithH2hysteresisloopssuggestingtheformationofmesophase.ThematerialswithlowZrincorporationcontenthaveanatasestructures;however,itcannotbefoundinthematerialswithhighZrincorporationcontent.TEMimagesshowthatsomeaccumulatedinter-particulateporesandwelldistributedworm-likeporesarepresentintheZr-incorporatedmaterials.

  • 标签: 中孔材料 二氧化钛 掺杂 溶胶-凝胶 结构
  • 简介:新奇thiol-functionalizedmesoporous硅石nanorods(MSNR)通过一个基础合作冷凝作用方法被综合,在哪个二organoalkoxysilanes,tetraethoxylsilane(TEOS)和二度[3-(triethoxysilyl)丙醇]tetrasulfide(TESPT),同时被用作硅石先锋。TESPT第一为形态学控制和mesoporous硅石混血儿材料的内部表面functionalization被使用。象MSNR的多孔的特性一样的微观结构借助于SEM,XRD,TEM和N2吸着大小被描绘。红外线的光谱分析和重金属离子(Ag+和Cd2+)吸附大小被执行证实MSNR的functionalized框架。

  • 标签: 介孔二氧化硅 表面功能化 重金属离子 吸附剂 巯基 合成
  • 简介:在最后20年里,因为他们的低biodegradability,从塑料生产的废物正在成为一个环境问题,变得明显。尽管几个方法为再循环浪费塑料被建议了,材料恢复不是现在的问题的一个长期的答案,这通常被接受,并且那个精力或化学恢复是一种更吸引人的选择,包括裂开进单体成分,生产精力的燃烧,并且生产有用中间的化学药品的热或催化的变换。这篇论文是在为精力恢复的最后选择的区域的贡献。有很多份出版物,为裂开聚合物进烃的一个范围报导分子的筛和非结晶的硅石氧化铝催化剂的使用。这里报导的研究工作表明我的能力在击碎聚乙烯进汽油的酣睡的催化剂变化产品。它为我被发现那酣睡的MCM-41催化剂,它有它的crystallinity的裂开的活动增加,与更小的毛孔直径显示更高的活动。烃产品分发强烈显示击碎机制的一个carbenium离子。产品分发也与从热裂开的测试获得的那些相比。

  • 标签: 废塑料 聚乙烯破裂 MCM-41 环境问题