| 摘 要： | The oxidative coupling of methane over various alkali metal oxidespromoted LaO_2O_3/BaCO_3 catalysts and the effects of Na_2O content on the performance of Na_2O-La_2O_3/Ba_2CO_3 catalyst have been studied.It was found thatNa_2O promoted La_2CO_3/BaCO_3 catalyst showed advantages of high CH_4 conver-sion,C_2 selectivity and C_2H_4/C_2H_6 ratio,Na_2O might affect the properties ofcatalyst through elctronic and geometric effuts.The highest C_2yield(19.0一20.6%)over Na_2-9wt%La_2O_3/BaCO_3 catalysts was obtained in the Na_2Ocontent range of 1.0—3.0%.Effects of reaction conditions on OCM over3wt% Na_2O-9wt%La_2CO_3/BaCO_3 catalyst were also investigated.The catalystswere characterized by BET,TPD,and XRD.TPD studies on 3wt% Na_2O-9wt%La_2O_3/BaCO_3 catalyst demonstrated that CO_2,CH_4.O_2could bestrongly on the catalyst.This might be related to the activation of CH_4 and theformation and reseneration of active oxygen soecies.
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