Selective epoxidation of alkenes with hydrogen peroxide over efficient and recyclable manganese oxides

A series of manganese oxides (MnO, Mn 3 O 4 , Mn 2 O 3 and MnO 2 ) were prepared and firstly applied as heterogeneous catalysts for the liquid phase epoxidation of alkenes with 30% H 2 O 2 in bicarbonate solution. Under our experimental conditions, MnO exhibited superior activity for the conversion of styrene to achieve ca. 100% with 92.4% selectivity of epoxide, compared to the other three manganese oxides as well as other metal oxides. Furthermore, recycling studies showed the good recyclability of MnO as a heterogeneous catalyst, which did not lose the catalytic activity after four reuses appreciably.