Prepration Of NiV₂O₆ Catalyst And Promoting Effect Of Ce On Its Catalytic Performances For Oxidative Dehydrogenation Of Propane

It is a challenging research topic to obtain higher propane conversion and higher propylene selectivity at the same time in the reaction of propane oxidative dehydrogenation (ODH). Under the ODH reaction conditions, it can be find that the total oxidation of propane and propylene occurs and to lead to the increase of propane conversion and the decrease of propylene selectivity. Therefore, it is very important to prepare a novel catalyst with a good catalytic behavior for propane ODH and to have high research significance.In this work, NiV2O6 and a series of Ce/NiV2O6 catalysts (Ce as promoter) were prepared and characterized, and their catalytic performance for oxidative dehydrogenation of propane to propylene was studied. The main research work as followings:Firstly, NiV2O6 catalyst was prepared by sol-gel method,solvent evaporation method and oxalate method respectively and characterized by TGA-DTA, XRD, BET, ICP, H2-TPR. The effect of preparation methods and calcination temperatures on catalytic performance of the catalysts was investigated. The results show that the catalyst prepared by sol-gel method and calcined at 600℃has better catalytic behavior for the oxidative dehydrogenation of propane.Secondly, NiV2O6 catalyst was prepared by sol-gel method using glucose, malic acid, glycin, citric acid as complex agent separately. Thermal effect and weight loss of precursor in the decomposition process were investigated by TGA-DTA. The physical and chemical properties of the catalyst were determined by XRD, ICP, BET, H2-TPR, SEM, TEM and XPS as well as their catalytic performances for the oxidative dehydrogenation of propane to propylene were studied. The results show that the optimized complex agent was glucose.Finally, XCe/NiV2O6 (X = 2%, 4%, 6%, 8%, 10%) catalysts were prepared by sol-gel method and characterized by XRD, BET, H2-TPR, XPS techniques. The promoting effect of Ce on the physical and chemical properties, the surface species and the surface properties of NiV2O6 catalyst, as well as the additive amount of Cerium on their catalytic performances for the oxidative dehydrogenation of propane to propylene were studied. The enhancement of the catalytic performance of NiV2O6 by Cerium addition was summarized.