| Autor: |
Trakarnpruk Wimonrat, Wannatem Apiwat, Kongpeth Jutatip |
| Jazyk: |
angličtina |
| Rok vydání: |
2012 |
| Předmět: |
|
| Zdroj: |
Journal of the Serbian Chemical Society, Vol 77, Iss 11, Pp 1599-1607 (2012) |
| Druh dokumentu: |
article |
| ISSN: |
0352-5139 |
| DOI: |
10.2298/JSC111124040T |
| Popis: |
A Keggin-type tungstocobaltate, [Co(2,2'- bipy)3]2H2[CoW12O40]•9.5H2O ([Co]CoW) and tetrabutylammonium salt of vanadium-substituted tungstophosphates [(n-C4H9)4N]4[PVW11O40], [(n-C4H9)4N]5[PV2W10O40] (PVW, PV2W) were used as catalyst for oxidation of cyclooctane with H2O2 as oxidant in acetonitrile. The activity of [(n-C4H9)4N4H[PCo(H2O)W11O39]•2H2O (PCoW) was also compared. The products of the reaction were cyclooctanone, cyclooctanol and cyclooctyl hydroperoxide. The experimental results showed that at H2O2/cyclooctane molar ratio = 3 at 80°C, in 9 h the [Co]CoW yielded higher conversion and selectivity to cyclooctanone. The V-based catalysts are more active than the Co-based tungstophosphate. The PV2W gave rise to high selectivity to cyclooctyl hydroperoxide. Cyclooctane conversion was increased by increasing reaction time or H2O2/cyclooctane molar ratio. In the presence of tungstocobaltate catalyst, 88% cyclooctane conversion and 82% selectivity of cyclooctanone were obtained after 12 h using H2O2/cyclooctane molar ratio of 9. This catalyst is stable upon treatment with H2O2. Experiments with radical traps suggest the involvement of a free-radical mechanism. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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