Abstract:  

　　Dielectric Barrier Discharge (DBD) plasma was successfully used for direct CO₂ dissociation (CO₂ splitting) and appears also as an interesting alternative technology to conventional catalytic dry reforming reaction. 

　　A recent study on the transformation of methane and carbon dioxide into synthesis gas performed by a plasma discharge coupled with a catalyst is described. Experiments were conducted at room temperature and 300°C, the catalyst being composed of lanthanum oxide deposited at the surface of alumina balls according to a classical incipient wetness method. The catalyst was placed into the plasma zone, filling it completely. The results in terms of reactants conversion and selectivity to products were compared with glass balls at a similar residence time into the plasma discharge. 

　　 The combination of the catalyst with the discharge does not modify significantly the transformation of reactants at room temperature whereas at 300°C, temperature at which the catalyst alone (10% La₂O₃/alumina balls) is inactive, the CH₄ conversion increases almost by a factor of 3 in comparison with glass balls, the CO₂ conversion being only slightly increased. The synergy between plasma and catalyst was then clearly demonstrated at 300°C whereas at room temperature the effect remains very low. It is proposed that the reaction between the oxygen species generated by CO₂ dissociation in gas phase (CO₂ splitting) replenish the surface oxygen species which have reacted with methane according to a Mars and Van Krevelen type mechanism.  

    联系人： DNL0901  王胜（9332）