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

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.

Nano silica was prepared from rice husk. Catalytic activity of H3PW12O40 supported on nano silica was investigated in Biginelli, Hantzsch, Mannich, and Claisen-Schmidt reactions.Figure optionsDownload as PowerPoint slide