Thesis (M.Sc.)--Chulalongkorn University, 2010

Polyoxometalates (POMs) were synthesized and characterized. The POMs were then supported on MCM-41 using different loading methods: incipient wetness impregnation method (10% 20% 30% and 40% based on weight of MCM-41) and impregnation method (11% based on weight of MCM-41). The supported catalysts were characterized by several techniques: XRD, XRF, FT-IR N2-adsorption and TGA. They were used as a catalyst for cyclohexane oxidation with 30% aqueous hydrogen peroxide or oxygen as oxidant. The oxidation products detected by GC were mainly cyclohexanol and cyclohexanone. Parameters affecting the oxidation reaction were studied. The optimum condition found was at 80°C, 8 h reaction time and the H2O2/cyclohexane molar ratio of 3. The result showed that the 20wt%CoPOM/MCM- 41 was the most active catalyst. The mechanism of the cyclohexane oxidation with H2O2 was proposed to occur via radical pathway. In addition, the catalysts can be reused for 3 times with slight drop of activity