Synthesis of adipic acid catalyzed by phosphotungstic acid supported on titania

H₃₂PW₁₂O₄₀/TiO₂ was prepared by phosphotungstic acid supported on titania.The effect of the catalyst H₃₂PW₁₂O₄₀/TiO₂ on direct oxidation of cyclohexene to adipic acid with 30% H₂O₂ was investigated.Results show that he yield of adipic acid is up to 55% when using 3.55 g H₃₂PW₁₂O₄₀/TiO₂,10.5 mL cyclohexene and 55 mL 30% H₂O₂ under 90℃ for 6 h.The amount of catalyst H₃₂PW₁₂O₄₀/TiO₂,the amount of 30% H₂O₂ and the effect of reaction time on the isolated yield of adipic acid was studied.Catalyst H₃₂PW₁₂O₄₀/TiO₂ can be reused.