Chem. J. Chinese Universities ›› 2021, Vol. 42 ›› Issue (9): 2734.doi: 10.7503/cjcu20210102

• Inorganic Chemistry • Previous Articles     Next Articles

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)

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

CLC Number: 

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