Highly Efficient Silica-Supported Peroxycarboxylic Acid for the Epoxidation of Unsaturated Fatty Acid Methyl Esters and Vegetable Oils

Abstract

A silica-supported peroxycarboxylic acid oxidant, 2-percarboxyethyl silica (SiO2@(CH2)2COOOH), was successfully prepared and used for the epoxidation of fatty acid methyl esters (FAMEs) and vegetable oils. Among the oxidants prepared under different conditions, C-SiO2@(CH2)2COOOH (TEOS:CTES = 2:1) had the highest surface area, pore volume, and peroxide value. It also exhibited the highest activity for the epoxidation reactions. For methyl linoleate, 92.76% yield of epoxidized product was obtained at room temperature. Other unsaturated FAMEs with 1 and 3 double bonds were also efficiently converted to their epoxides. Moreover, the oxidant was also successfully applied to the epoxidation of vegetable oils, olive oil, and linseed oil with high product yield at room temperature. Finally, the used oxidant was regenerated through a simple oxidation process with H2O2 and recycled at least 5 times without much drop in the reactivity.