Mesostructured SBA-16 with excellent hydrothermal, thermal and mechanical stabilities: Modified synthesis and its catalytic application

We report a modified method to synthesize SBA-16 mesostructured Silica under refluxing condition using block co-polymer poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (F127) as template, cetyltrimethylammonium bromide (CTAB) as co-template, and tetraethyl orthosilicate (TEOS) as silica source. The physiochemical properties of SBA-16 silica were characterized by X-ray diffraction (XRD), nitrogen physisorption, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Si-29 solid-state nuclear magnetic resonance (NMR). The resulting SBA-16 silica exhibited highly ordered mesoporous structure, mono-dispersed spherical morphology, excellent hydrothermal, thermal and mechanical stabilities. It was worth mentioning that the synthesis time can be significantly reduced from 48 h to 8 h, which opened a feasible way to produce SBA-16 silica in a large scale. Moreover, the super-cage pore structure of SBA-16 encapsulated gold nanoparticles in a ship in a bottle way. The well-confined gold nanoparticles (mean size of 5 nm) with a narrow particle size distribution were highly active in solvent-free benzyl alcohol selective oxidation with molecular oxygen. (c) 2009 Elsevier Inc. All rights reserved.