Study On RE/Ni-V-O Composite Oxide Catalysts For Oxidative Dehydrogenation Of Propane To Propene

In this thesis, the appropriate catalysts for oxidative dehydrogenation of propane were chosen through the results of catalytic activity evaluation in a fixed-bed microreactor. Parameters of catalyst preparation and reaction condition were also identified. The influences of the preparation methods of catalyst as well as addition promoter of rare earth oxide on the catalytic performance were also investigated.Firstly, Ni₃V₂O₈ catalysts were separately prepared by nitrate method, citric acid sol-gel method, solid rubbing method, oxalate co-precipitation, microwave method and ultrasonic method. The effect of baking temperature was investigated and the catalysts were characterized by BET, XRD, H2-TPR, XPS and in situ electrical conductivity. The results show that the optimized catalyst was prepared by ultrasonic method.Secondly, the catalytic performances of Ni-V-O catalysts were studied. When Ni:V=3:2, the p-semiconductor Ni₃V₂O₈ possess optimal catalytic performance, 31.78% conversion of propane and 34.31% propene selectivity at 400℃.Finally, the catalytic performance of Ni₃V₂O₈ catalysts was improved with the addition of promoter rare earth oxide. The promoter light rare earth can decrease the conversion of propane and enhance the selectivity of propene. The best result achieve with the addition of Nd. The influence of the addition method and quantity for catalytic performance is inconspicuous.