| 摘 要： | The effect of Li.La.Mn and W added to TiO_2 on catalyticperformance for the oxidation coupling of methane (OCM)and on TiO_2 phasetransition was discussed.X-ray diffraction(XRD)analysis and differentialthermal analysis-thermogravimentric analysis (DTA TGA) were used to studythe relation between TiO_2 phase transition and OCM reaction performance.Theresults showed that Li-La-Mi-W/TiO_2 system exhibited high activity andC_2 hydrocarbon selectivity.Anatase TiO_2(A)and rutile TiO_2(R)exhibiteddifferent OCM activity and selectivity.TiO_2(A)is favorable for the activationof methane.TiO_2(R)is favorable to the formation of C_2 hydrocarbons.Lipromutes the transformation from TiO_2(A) to TiO_2(R)and enhancesC_2 selectivity.La has nothing to do with TiO_2 phase shift.it raises mtehaneconversion,resulting in deep oxidation.Li and La simultaneously added toTiO_2 exhibit a cooperation.
|
