Abstract: The role of plasma activation in the direct gas phase epoxidation of propylene with molecular oxygen is discussed for the first time. The plasma was obtained by applying pulse corona discharge to the mixture of oxygen and propylene at room temperature and atmospheric pressure by using a needle-plate reactor. The reaction mixture was analyzed by an on-line chromatography. The effects of some main parameters on propylene conversion, PO yield and PO selectivity, such as the space between the electrodes, the pulse discharge frequency as well as the pulse discharge voltage, were investigated. It is observed that, at room temperature and atmospheric pressure, propylene and oxygen can be directly converted into PO in gas phase only by plasma activation. The proper adjustment of above parameters can rise the yield of PO. When the pulse voltage of corona discharge is fixed at 18 kV, the yield of PO, the conversion of propylene and the selectivity of PO are 5.15%, 19.15% and 26.89%, respectively.

Key words: Pulse corona discharge, Plasma, Molecular oxygen, Propylene oxide(PO)