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1、第*期作者等:文章題目·9·Ce改性硅鎢酸催化制備月桂酸單甘酯朱廣琪1，李佳敏1，張曉芳1，韓曉祥1*，唐秀娟2，王奎武1，王彥波1*（1.浙江工商大學(xué)應(yīng)用化學(xué)系，浙江杭州310018；2.浙江工商大學(xué)環(huán)境科學(xué)與工程學(xué)院浙江杭州310018）摘要：采用離子交換法合成多種稀土改性硅鎢酸催化劑MxH4–3xSiW12O40(M=La,Ce,Pr,Nd,Sm;x=1/3,2/3,1,4/3)，并利用FTIR，XRD，TGA-DTG，固體核磁共振結(jié)合探針分子技術(shù)(31P-TMPOMAS-NMR)對(duì)CexH4–3xSiW12O40催化劑結(jié)構(gòu)、穩(wěn)定性及酸性進(jìn)行了表征；結(jié)果表明，Ce1/3H3Si
2、W12O40催化劑在月桂酸單甘酯制備中顯示出最好的催化性能。稀土Ce有效結(jié)合到硅鎢酸上，制備的催化劑保持了完整的Keggin結(jié)構(gòu)。與純硅鎢酸相比，CexH4–3xSiW12O40的酸強(qiáng)度有所減弱，但由于該類催化劑較強(qiáng)的Br?nsted酸性及Br?nsted-Lewis酸性位間的協(xié)同效應(yīng)，使CexH4–3xSiW12O40在月桂酸單甘酯的制備中具有良好的催化性能。以Ce1/3H3SiW12O40為催化劑，在甘油/月桂酸物質(zhì)的量比為4/1，催化劑用量為月桂酸質(zhì)量的4%，反應(yīng)溫度423K，反應(yīng)時(shí)間120min下，月桂酸單甘酯產(chǎn)率為78.4%；動(dòng)力學(xué)研究表明，該反應(yīng)活化能為42.37kJ/m
3、ol；Ce1/3H3SiW12O40催化劑經(jīng)5次回收利用，月桂酸單甘酯的產(chǎn)率為71.4%，具有較好的重復(fù)使用性能。關(guān)鍵詞：稀土；硅鎢酸；酯化反應(yīng)；月桂酸單甘酯；催化技術(shù)中圖分類號(hào)：O643.32文獻(xiàn)標(biāo)識(shí)碼：A文章編號(hào)：CatalyticPropertiesofCeExchangedTungstosilicicAcidontheEsterificationtoGlycerolMonolaurateZHUGuang-qi1,LIJia-min1,ZHANGXiao-fang1,HANXiao-xiang1*,TANGXiu-juan2,WANGKui-wu1,WANGYan-bo1*(1
4、.DepartmentofAppliedChemistry,ZhejiangGongshangUniversity,Hangzhou310018,Zhejiang,China;2.CollegeofEnvironmentalScienceandEngineering,ZhejiangGongshangUniversity,Hangzhou310018,Zhejiang,China)Abstract:AseriesofrareearthmodifiedtungstosilicicacidcatalystsMxH4-3xSiW12O40(M=La,Ce,Pr,Nd,Sm;x=1/3,2/
5、3,1,4/3)werepreparedbyionexchangemethod.Thestructure,stabilityandacidityofthecatalysts(CexH4-3xSiW12O40)werecharacterizedbydifferentanalyticalandspectroscopictechniquessuchasFT-IR,XRD,TGA-DTGand31PMAS-NMR,andtheircatalyticpropertieswereinvestigatedontheesterificationoflauricacid(LA)andglycerol(
6、GL)toglycerolmonolaurate(GML).ResultsshowedthatCe1/3H3.0SiW12O40catalysthadthebestcatalyticactivityinthesynthesisofGML.Therareearthmetalcation(Ce)hadbeeneffectivelycombinedtotungstosilicicacid,andthecatalystsmaintainedthecompleteKegginstructure.Comparedwithtungstosilicicacid,theacidityofCexH4-3
7、xSiW12O40catalystsdecreased,butthecatalystshadgoodcatalyticperformanceduringtheesterificationforstrongBr?nstedacidityandBr?nsted-Lewisacidsynergy.TheCe1/3H3.0SiW12O40wasutilizedtooptimizethereactionconditionswith78.4%GMLyieldunder
