Preparation and characterization of CuO-CoO-MnO/SiO2
nanocomposite aerogels as catalyst carriers
nanocomposite aerogels as catalyst carriers
(1. College of Light Industry, Hebei Polytechnic University, Tangshan 063000, China;
2. College of Materials Science and Engineering,
University of Science and Technology Beijing, Beijing 100083, China;
3. College of Chemical Engineering, Hebei Polytechnic University, Tangshan 063009, China;
4. College of Materials Science and Engineering, Hebei Polytechnic University, Tangshan 063009, China)
2. College of Materials Science and Engineering,
University of Science and Technology Beijing, Beijing 100083, China;
3. College of Chemical Engineering, Hebei Polytechnic University, Tangshan 063009, China;
4. College of Materials Science and Engineering, Hebei Polytechnic University, Tangshan 063009, China)
Abstract: CuO-CoO-MnO/SiO2 nanocomposite aerogels were prepared by using tetraethyl orthosilicate (TEOS) as Si source, and aqueous solution of Cu, Co and Mn acetates as the precursors via sol-gel process and ethanol supercritical drying technique. The gelatination mechanism was investigated by nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS). The microstructure and composition of the CuO-CoO-MnO/SiO2 nanocomposite aerogels were characterized by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), electron dispersive spectroscopy (EDS) and XPS. The specific surface area, pore size and pore size distribution of the nanocomposite aerogels were determined by the Brunauer–Emmett–Teller (BET) method. The products were analyzed by gas chromatography (GC). The results show that the CuO-CoO-MnO/SiO2 nanocomposite aerogels are porous, with a particle size distribution of 10–150 nm, a pore size distribution of 2–16 nm, an average pore size of 7.68 nm, and a specific surface area of 664.4−695.8 m2/g. The molar fraction of transition metals in the nanocomposite aerogels is 0.71%−13.77%. This kind of structure is favorable not only to increase the loading of catalysts, but also to make full use of the effect of transition metal oxides as cocatalysts; CuO-CoO-MnO/SiO2 nanocomposite aerogels can be used as a novel catalyst carrier in the safer and environment-friendly synthesis of diphenyl carbonate and other fields of catalysis.
Key words: nanocomposite aerogel; preparation; characterization; catalyst carrier