Abstract: The anatase TiO2 nanoparticles were prepared by heat treating TiO2 precursor, which was made from Ti(SO4)2 and washed with ethanol, in an autoclave under the conditions of 270 ℃ and 7.07 MPa. The catalyst was used to catalyze α-pinene epoxidation with air. The results showed that the catalyst activity increased markedly after heat treating with ethanol under high pressure. Under the conditions of 101.325 kPa, 70 ℃ and 6 h, the α-pinene conversion reached 17.02% and the selectivity for epoxides was 53.47%. When the system pressure increased to 1.01 MPa, the conversion increased to 35.24% and the epoxide selectivity decreased to 41.20%. The possible reaction mechanism has also been investigated.

Key words: nanosized titanium dioxide, ethanol, air, pinene, epoxidation