Limonene epoxidation in aqueous phase over Ti/KIT-6

Abstract

Limonene epoxidation was carried out in the liquid phase using Ti/KIT-6 as the catalyst and tert-butyl hydroperoxide as oxidant. The best selectivity (60%) was obtained at 50 °C after 7 h of reaction, and the conversion was 23%. The main side products were carvone, carveol, 1,2-epoxylimonene diol, perillyl alcohol and p-mentha-2,8-dien-1-ol. The catalyst does not leach under reaction conditions and it can be reused after calcination at 550 °C. The catalyst was characterized by atomic absorption, XRD, UV-vis and N 2 adsorption isotherms.