Effect of the conditions of preparing titanium-containing zeolite on its catalytic activity in the epoxidation of olefins with hydrogen peroxide

Abstract

The results from systematic studies of the conditions for obtaining a titanium-containing zeolite and its catalytic activity in the liquid-phase epoxidation of olefins with an aqueous solution of hydrogen peroxide in a medium of methanol are described. The yield of olefin oxides was taken as a criterion of activity of the catalyst. The highest catalytic activity was found in the samples that had the initial molar ratio of tetrabutoxy titanium (TBOT) to tetraethoxysilane (TEOS) of 0.04–0.06 and the molar ratio of tetrapropylammonium hydroxide (TPAH) to TEOS of 0.25–0.5 and were subjected to a hydrothermal processing at 170°C for 40–60 h. The titanium-containing zeolite was rinsed either with demineralized water or with methyl alcohol. Calcination was performed at 550°C. The catalyst synthesized under optimum conditions allows us to derive olefin oxides with a yield of 90–95%, accompanied by the quantitative conversion of hydrogen peroxide.