Oxidation of styrene oxide via chemical and photochemical methods using TiO₂-CeO₂-V₂O₅ catalysts

This work reports the preparation of the TiO₂-CeO₂ (TiCe) catalytic support of V₂O₅ catalysts, which was tested in the oxidation process of styrene oxide via chemical and photochemical methods. The TiCe-V₂O₅ catalytic support was prepared by the co-precipitated method from the individual metal oxides, varying the amount of vanadium oxide by 3, 6, and 10 % mol with respect to the support. The obtained catalysts were characterized by different spectroscopies, as well as by the N₂ adsorption-desorption technique. The catalytic reaction test was carried out in the liquid phase during 120 min with/without ultraviolet light irradiation at 50 °C. There was no V₂O₅ effect on the surface area, pore volume, and pore diameter since all catalysts had similar textural values. In all samples the structures identified by X-ray diffraction were the Anatase phase and CeO₂ in the cubic phase. XPS results revealed the formation of surface carbonate species, which were also identified by infrared spectroscopy. The conversion rate was better when employing ultraviolet light, and the rate increased as the V₂O₅ amount rose. The main reaction products were 2-phenylethanol and 1-phenylethanol. However, a low amount of benzaldehyde was detected. The selectivity to the desirable product (2-phenylethanol) increased when the reaction was irradiated with UV light and the catalyst contained a higher amount of vanadium. It was observed that the effect of UV radiation on the electric mobility produces an acceleration of the reaction to 2-phenylethanol, avoiding the 1-phenylethanol formation. The bandgap value decreased as the vanadium oxide amount increased, boosting the electric mobility.