催化学报 ›› 2012, Vol. 33 ›› Issue (8): 1326-1333.DOI: 10.1016/S1872-2067(11)60420-8

• 研究论文 • 上一篇    下一篇

Nano Silica with High Surface Area from Rice Husk as a Support for 12-Tungstophosphoric Acid: An Efficient Nano Catalyst in Some Organic Reactions

Ezzat RAFIEE1,2,*, Shabnam SHAHEBRAHIMI1   

  1. 1Faculty of Chemistry, Razi University, Kermanshah 67149, Iran; 2Kermanshah Oil Refining Company, Kermanshah, Iran
  • 收稿日期:2012-01-30 修回日期:2012-05-05 出版日期:2012-08-01 发布日期:2012-08-01

Nano Silica with High Surface Area from Rice Husk as a Support for 12-Tungstophosphoric Acid: An Efficient Nano Catalyst in Some Organic Reactions

Ezzat RAFIEE1,2,*, Shabnam SHAHEBRAHIMI1   

  1. 1Faculty of Chemistry, Razi University, Kermanshah 67149, Iran; 2Kermanshah Oil Refining Company, Kermanshah, Iran
  • Received:2012-01-30 Revised:2012-05-05 Online:2012-08-01 Published:2012-08-01

摘要: Nano silica was prepared from rice husk with high surface area. X-ray diffraction (XRD) pattern showed that the amorphous form of silica was produced. Chemical composition of the nano silica was estimated by X-ray fluorescence spectroscopy and CHN analysis. The nano silica was used as a support for H3PW12O40. The nano silica and nano silica supported H3PW12O40 were characterized by inductively coupled plasma, XRD, transmission electron microscopy (TEM), N2 adsorption-desorption, and Fourier transform infrared spectroscopy. TEM images of nano silica as well as the supported catalyst displayed average size of 6 and 7 nm, respectively. The catalyst showed excellent activity in some important organic reactions including Biginelli, Hantzsch, Mannich, and Claisen-Schmidt reactions with good reusability. Catalytic activity of this nano catalyst is an improvement over the commercially available silica that is used to support H3PW12O40.

关键词: amorphous silica, heteropolyacid, heterogeneous catalysis, nano catalyst, rice husk

Abstract: Nano silica was prepared from rice husk with high surface area. X-ray diffraction (XRD) pattern showed that the amorphous form of silica was produced. Chemical composition of the nano silica was estimated by X-ray fluorescence spectroscopy and CHN analysis. The nano silica was used as a support for H3PW12O40. The nano silica and nano silica supported H3PW12O40 were characterized by inductively coupled plasma, XRD, transmission electron microscopy (TEM), N2 adsorption-desorption, and Fourier transform infrared spectroscopy. TEM images of nano silica as well as the supported catalyst displayed average size of 6 and 7 nm, respectively. The catalyst showed excellent activity in some important organic reactions including Biginelli, Hantzsch, Mannich, and Claisen-Schmidt reactions with good reusability. Catalytic activity of this nano catalyst is an improvement over the commercially available silica that is used to support H3PW12O40.

Key words: amorphous silica, heteropolyacid, heterogeneous catalysis, nano catalyst, rice husk