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Free keywords:
alumina;
catalytic epoxidation;
green chemistry;
hydrogen peroxide;
sol-gel
Abstract:
It is shown that sol-gel alumina calcined at 400 0C is a very efficient catalyst for the epoxidation of cyclohexene and cyclooctene with aqueous 70 wt % hydrogen peroxide. The overall yield per g of catalyst was 0.28 mol of cyclohexene oxide in 5 cycles of 450 min each and 0.43 mol of cyclooctene oxide in 4 cycles of 750 min each. The selectivity for the epoxides was always better than 99%. However, the catalyst deactives slowly, which we believe is caused by a non-radical decomposition of hydrogen peroxide.