Chemical Research in Chinese Universities ›› 2018, Vol. 34 ›› Issue (2): 247-253.doi: 10.1007/s40242-018-7296-x

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Fluorine Modified TAPO-5: Synthesis and Catalytic Performance in Cyclohexanone Ammoximation

LI Hengjie, GAO Pengfei, XUE Xiaolu, ZHANG Hongxi, ZHAO Yongxiang   

  1. School of Chemistry and Chemical Engineering, Engineering Research Centre of Ministry of Education for Fine Chemicals, Shanxi University, Taiyuan 030006, P. R. China
  • Received:2017-09-07 Revised:2017-11-03 Online:2018-04-01 Published:2017-11-22
  • Contact: GAO Pengfei,E-mail:pfgao@sxu.edu.cn;ZHAO Yongxiang,E-mail:yxzhao@sxu.edu.cn E-mail:pfgao@sxu.edu.cn;yxzhao@sxu.edu.cn
  • Supported by:
    Supported by the National Natural Science Foundation of China(Nos.21403135, 21303097, 21305082), and the Science and Technology Research Project of Shanxi Province, China(Nos 201603D121018-1).

Abstract: A series of fluorine modified TAPO-5 molecular sieves was synthesized by one-pot method using ammonium hexafluorotitanate as titanium and fluorine sources. The XPS and DRS UV-Vis results indicated that the existence of F could promote the formation of tetrahedrally coordinated framework Ti and Al, meanwhile, inhibit the formation of anatase TiO2 in TAPO-5 sieves due to the unique role of F in the sol-gel process of metal ions. Furthermore, TG, contact angle test, Py-FTIR and 27Al MAS NMR results revealed that fluorine modification increased the surface hydrophobicity and the Lewis acidity of Ti active sites through forming AlxFy units in the neighborhood. All these factors make these fluorine modified TAPO-5 sieves exhibit good catalytic performance in the ammoximation of cyclohexanone.

Key words: TAPO-5, Fluorine modification, Hydrophobicity, Lewis acidity, Cyclohexanone ammoximation