Non-aqueous template-assisted synthesis of mesoporous nanocrystalline silicon orthophosphate
| Authors | |
|---|---|
| Year of publication | 2015 |
| Type | Article in Periodical |
| Magazine / Source | RSC Advances |
| MU Faculty or unit | |
| Citation | |
| Doi | http://dx.doi.org/10.1039/c5ra10982e |
| Field | Inorganic chemistry |
| Keywords | PHOSPHORIC-ACID CATALYST; ORGANIC-INORGANIC HYBRID; SOL-GEL SYNTHESIS; PHOSPHOSILICATE GELS; AMBIENT CONDITIONS; CRYSTAL-STRUCTURE; MOLECULAR-SIEVES; SURFACE-AREA; MAS NMR; GLASSES |
| Description | The first synthesis of mesoporous nanocrystalline silicon orthophosphate Si5P6O25 is presented. The synthetic procedure is based on the non-hydrolytic sol-gel reaction in the presence of Pluronic P123 template and subsequent calcination in air. The condensation of silicon acetate, Si(OAc)(4), and tris(trimethylsilyl) phosphate, OP(OSiMe3)(3) (TTP), in non-aqueous solvents driven by elimination of trimethylsilyl acetate provides a homogeneous network with a high content of Si-O-P bonds and SiO6 moieties. After burning out the template, mesoporous silicon orthophosphate was obtained with surface areas up to 128 m(2) g(-1) and pore sizes around 20 nm. The nanocrystalline Si5P6O25 phase forms relatively easily (500 degrees C, 4 h) in comparison with other synthetic routes. All samples were characterized by SEM, TEM, elemental analysis, TGA, nitrogen adsorption, SAXS, H-1, C-13, Si-29, and P-31 solid-state NMR spectroscopy, and powder XRD. These xerogels showed superior catalytic activity and selectivity in methylstyrene dimerization. |
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