Preparation and characterization of CuO(CoO, MnO)/SiO2nanocomposite aerogels as catalysts carrier by sol-gel process

CuO(CoO, MnO)/SiO2nanocomposite aerogels were prepared from tetraethyl orthosilicate (TEOS) and acetate of Cu, Co and Mn via sol-gel process and ambient pressure drying technique. The effect of mass ratio of transition metal-oxides to SiO2, preparation temperature and pH value on gelation was investigated. The microstructure and composition of CuO(CoO, MnO)/SiO2nanocomposite aerogels were analyzed by field emission scanning electron microscope, BET, Fourier transform infrared spectrum, thermogravimetric and differential thermal analysis, electron dispersive spectrum and chemical analysis. The results show that CuO(CoO, MnO)/SiO2nanocomposite aerogels are porous with particle size distribution of 20-100 nm, surface area of 344-733 m2/g, and pore size distribution of 2-16 nm. In addition, bridge bonds of -O-M-O- can be formed to some extent by the chemical bonding of transition metals and oxygen, and three-dimensional network structure is formed by the chemical bonding of Si and -O-M-O-. The mass fraction of transition metal-oxides in the nanocomposite aerogels is in the range of 3%-75wt%. This kind of structure and composition is not only favorable to the increase of the catalysts loading, but also to the effective use of transition metal-oxides as catalyst accelerators.