高等学校化学学报 ›› 2021, Vol. 42 ›› Issue (9): 2734.doi: 10.7503/cjcu20210102

• 无机化学 • 上一篇    下一篇

介孔磷钨酸铯盐的液相组装及酸性研究

王美银, 黄道丰, 陈欣, 周俊夫, 任远航, 叶林, 岳斌(), 贺鹤勇()   

  1. 复旦大学化学系, 上海市分子催化与功能材料重点实验室, 上海 200438
  • 收稿日期:2021-02-18 出版日期:2021-09-10 发布日期:2021-09-08
  • 通讯作者: 岳斌 E-mail:yuebin@fudan.edu.cn;heyonghe@fudan.edu.cn
  • 作者简介:贺鹤勇, 男, 博士, 教授, 主要从事多相催化和固体核磁共振波谱研究. E-mail: heyonghe@fudan.edu.cn
  • 基金资助:
    国家自然科学基金(22088101);国家重点研发计划项目(2017YFB0602204);中国石油化工股份有限公司研究项目(420068-2)

Liquid Phase Assembly of Mesoporous CsxH3-xPW12O40 and Characterization of Their Acidity

WANG Meiyin, HUANG Daofeng, CHEN Xin, ZHOU Junfu, REN Yuanhang, YE Lin, YUE Bin(), HE Heyong()   

  1. Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials,Fudan University,Shanghai 200438,China
  • Received:2021-02-18 Online:2021-09-10 Published:2021-09-08
  • Contact: YUE Bin E-mail:yuebin@fudan.edu.cn;heyonghe@fudan.edu.cn
  • Supported by:
    the National Natural Science Foundation of China(22088101);the National Key Research & Development Program of China(2017YFB0602204);the SINOPEC Research Project, China(420068?2)

摘要:

以磷钨酸(H3PW12O40)和氯化铯(CsCl)为原料, 两亲型三嵌段共聚物F127为模板剂, 按不同的Cs/P比制备了一系列介孔磷钨酸铯盐(CsxH3-xPW12O40, m-CsPW). 通过X射线粉末衍射(XRD)、 场发射扫描电子显微镜(FESEM)、 场发射透射电子显微镜(FETEM)、 N2吸附-脱附测试和小角X射线散射(SAXS)等手段对所得样品进行了表征. 结果表明, 样品是由纳米微晶组装而成的晶态介孔材料. 以三甲基膦为探针分子, 通过31P魔角旋转固体核磁共振波谱(31P MAS NMR)测定了样品酸处理前后的酸密度和酸强度. 以5,7-二羟基-4-甲基香豆素的Pechmann缩合反应为模型反应, 考察了样品的酸性质与催化活性之间的关系.

关键词: 介孔多酸盐, 31P魔角旋转固体核磁共振波谱, 酸性, Pechmann缩合

Abstract:

A series of mesoporous CsxH3-xPW12O40 samples(denoted as m-CsPW) has been prepared using H3PW12O40, CsCl as raw materials and amphiphilic triblock copolymer F127 as template. The sampleswere characterized by means of powder X-ray diffraction(XRD), field emission scanning electron microscopy (FESEM), field emission transmission electron microscopy(FETEM), N2 adsorption-desorption measurement and small angle X-ray scattering(SAXS) spectroscopy. The results indicate that the m-CsPW particles consis-ting of crystallographically ordered nanocrystallites are mesoporous spherical materials. Acid density and strength of the samples before and after acid treatment were characterized by 31P magic-angle spinning NMR spectroscopy(31P MAS NMR) using trimethylphosphine as probe molecule. Taking the Pechmann condensation of 5,7-dihydroxy-4-methylcoumarin as a model reaction, the relationship between the acid properties of the samples and the catalytic activity of the reaction has been investigated.

Key words: Mesoporous polyoxometalate, 31P magic-angle spinning NMR spectroscopy(31P MAS NMR), Acidic property, Pechmann condensation

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