Ecofriendly catalysts based on mixed xerogels for liquid phase oxidations by hydrogen peroxide

In this study TiO2-CeO2 and TiO2-V2O5 mixed oxide were synthesized by sol-gel technique. The mixed xerogels were prepared with different load of TiO2 and CeO2 or V2O5, using titanium isopropoxide and hexahydrated cerium nitrate or vanadyl acetylacetonate as precursors, and ethanol (99.8%) as solvent. The gels were dried in air at 50°C for 24h and calcined in air at temperatures in the range 200–800°C for 4h. Moreover, a sample without cerium, 100% (w/w) TiO2, was prepared to be kept as reference material. The prepared solids were characterized by means of XRD, FT-IR and TEM. Their textural properties were determined by adsorption-desorption isotherms of N2 at 77K. The xerogels were tested as catalysts in the liquid phase oxidation of 2,6- dimethylphenol to 2,6-dimethyl-p-benzoquinone at 20°C, using ethanol as solvent and aqueous hydrogen peroxide as a clean oxidizing agent.