ti_hms催化剂的制备及其催化丙烯环氧化_刘红梅

《ti_hms催化剂的制备及其催化丙烯环氧化_刘红梅》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、石油化工2011年第40卷第11期PETROCHEMICALTECHNOLOGY·1165·Ti－HMS催化剂的制备及其催化丙烯环氧化刘红梅，张明森，柯丽，王斌，满毅(中国石化北京化工研究院，北京100013)［摘要］以长链伯胺为模板剂、正硅酸乙酯和钛酸四丁酯为原料制备了Ti－HMS介孔分子筛，经硅烷化处理后得到Ti－HMS催化剂并将其应用于丙烯环氧化反应。采用XRD、N2吸附－脱附和UV－Vis等表征手段研究了合成母液中水与乙醇的体积比(简称水醇比)、模板剂分子链长度、钛含量等因素对Ti－HMS催化剂结构特

2、性的影响。表征结果显示，合成母液中加入适量水能提高催化剂的介孔有序度并增大比表面积和孔体积，最佳水醇比为0．30～0．60。采用分子链较长的模板剂或减少钛含量能促使钛原子进入HMS分子筛骨架中，同时增大比表面积、孔径、孔体积和孔壁厚度。Ti－HMS催化剂上同时存在骨架四配位钛物种和骨架外六配位钛物种，前者是催化丙烯环氧化反应的关键活性位，而后者则会引起氧化剂无效分解。［关键词］Ti－HMS催化剂;丙烯;环氧化;环氧丙烷［文章编号］1000－8144(2011)11－1165－07［中图分类号］TQ426．94

3、［文献标识码］APreparationandCatalyticPerformanceofTi-HMSCatalystinPropyleneEpoxidationLiuHongmei，ZhangMingsen，KeLi，WangBin，ManYi(SINOPECBeijingResearchInstituteofChemicalIndustry，Beijing100013，China)［Abstract］Mesoporousmolecularsievescontainingtitanium，Ti-HMS，wer

4、epreparedfromtetraethylorthosilicateandtetrabutylorthotitanatewithlong-chainprimaryaminesurfactantsastemplates，andcharacterizedbymeansofXRD，N2adsorption-desorptionandUV-Vistechniques．ThecatalyticperformancesofthesilylanizedTi-HMSinpropyleneepoxidationwerein

5、vestigated．TheeffectsofH2O/EtOHvolumeratioinsynthesismotherliquors，chainlengthofthetemplatemoleculeandTicontentontheTi-HMScatalyststructurewerestudied．Itwasindicatedthat，additionofaproperamountofwaterintothesynthesismotherliquorscouldimprovethemesoporeorder

6、ingintheTi-HMScatalysts，andincreasetheirspecificsurfaceareasandporevolumes．TheoptimumH2O/EtOHvolumeratiowasintherangeof0．30to0．60．AtemplatewithlongmolecularchainorlowTicontentwasconducivetotheintroductionofTiatomsintotheframeworkofthemesoporousmolecularsiev

7、es．Thespecificsurfaceareas，porediameters，porevolumesandwallthicknessesoftheTi-HMScatalystsincreasedwiththeincreaseofchainlengthsinthetemplatemolecules．Itwastestifiedthat，thereweretwoTispecies，tetrahedral-coordinatedandoctahedral-coordinatedTiatoms，intheTi-H

8、MScatalysts．Theformerwasthekeyactivesitesfortheepoxidationwhilethelatterwouldleadtononeffectivedecompositionoftheoxidant．［Keywords］Ti-HMScatalyst;propylene;epoxidation;propyleneoxide环氧丙烷(PO)是一种重要的基础化工原