The effect of calcination temperature on V-Ti oxides catalysts for gas oxidation of 1,2,4,5-tetramethylbenzene to pyromellitic dianhydride
V-Ti oxides catalysts were prepared by impregation and calcinated at different temperature and tested in a fixed bed reactor for durene oxidation to pyromellitic dianhydride (PMDA) .The physical-chemical properties of catalysts were characterized by XRD,Raman and H2-TPR method.The results showed that the vanadium in the catalyst was mainly in the form of crystal V2O5 and surface VOx species on the TiO2.The ratio of surface VOx species and crystal V2O5 in catalyst can be influenced by calcination temperature,and the higher temperature,the more V2O5 and polymerized VOx species it was in the cata-lyst.The catalyst calcinated at 500 ℃ has a highest PMDA yield of 85.8％ in the reaction of durene oxidation as the reducibility was moderate and the weak acidity was more.
catalyst engineeringV-Ti oxide catalystspyromellitic dianhydridegas oxidationcalcination temperature
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维普
