Catalysis Letters, Vol.142, No.6, 788-793, 2012
Organic-Inorganic Hybrid SiO2 Supported Gold Nanoparticles: Facile Preparation and Catalytic Hydrogenation of Aromatic Nitro Compounds
Highly dispersed gold nanoparticles supported on organic-inorganic hybrid silica have been successfully prepared through a novel and facile approach. In the process, 3-aminopropyltriethoxysilane was hydrolyzed in HCHO aqueous solution to prepare silica with organic functional groups (-SiCH2CH2CH2NHCH2OH) formed through the reaction between -NH2 and HCHO, then the silica reacted with HAuCl4 in aqueous solution. Due to the reducibility of -SiCH2CH2CH2NHCH2OH, the gold precursor was in situ reduced on the silica. The materials were characterized by powder X-ray diffraction, transmission electron microscopy, Fourier-transform infrared spectroscopy, solid-state nuclear magnetic resonance spectroscopy, and X-ray photoelectron spectroscopy techniques. The results indicated Au nanoparticles were highly dispersed on silica with an average particles size 1.8 +/- A 0.5 nm. The as-obtained Au/SiO2-org exhibited good catalytic activity and stability for liquid phase catalytic hydrogenation of aromatic nitro compounds with H-2. Highly dispersed gold nanoparticles supported on organic-inorganic hybrid silica have been successfully prepared through a new facile approach. In the process, one-pot preparation of SiO2-org with -SiCH2CH2CH2NHCH2OH groups and in situ reduction of gold ions in aqueous solution to form gold nanoparticles on SiO2-org are performed. The as-obtained catalysts with Au particles in size of 1.8 +/- 0.5 nm show high activity and selectivity for hydrogenation of aromatic nitro-compounds.