Studies On Catalytic Performances Of Mesoporous NiO, V/meso-NiO And Ni-V Composite Oxide Catalysts For Oxidative Dehydrogenation Of Propane To Propene

Improving propane conversion and propene selectivity under lowtemperature is vital for oxidative dehydrogenation of propane （ODHP） topropene. Considerable interest has been focused on the catalysts with highperformance under lower temperature. Aims to the ODHP reaction,parameters of catalyst preparation method of meso-NiO were optimized. Thenthe Ni_xV_1-xO_ypossesses large surface area as well as V/meso-NiO catalystswere prepared using a similar procedure to meso-NiO. The influences of porestructure and Ni/V ratio on the catalytic performance were investigated.1. NiO catalysts were prepared using nickel nitrate and nickel acetaterespectively. The influences of Ni source and preparation method on catalyticperformance were investigated. The catalysts were characterized by N₂adsorption-desorption measurements, XRD, H₂-TPR and XPS. The resultsshow that meso-NiO can be synthesized by soft-template method using Nickelacetate source. Considerable amounts of adsorbed oxygen species exist in thesample, which arributes to propene selectivity and catalytic stability.2. Meso-NiO was synthesized using polyethylene glycol （PEG） astempelate and urea as precipitation agent. The influences of PEG addition,calcining temperature and PEG molecular weight on the catalyticperformance were studied. Mesoporous structure formed by PEG additionbefore precipitation. The calcining temperature is favorable to the formationof NiO phase and mesoporous structure. The PEG molecular weight affectcatalytic performance is slightly.3. The preparation of PEG as template is comparable to that of CTAB.Irregular porous Ni_xV_1-xO_ycomposite oxides prepared by PEG soft-templatemethod possesse large surface area and high catalytic performance. Forcomparision, we introduced vanadium by different Ni/V molar ratio and obtained better catalytic performance over the Ni_0.9V_0.1O_ycatalyst with NiOand Ni₃V₂O₈phase.4. Active species vanadium was introduced by wetness impregnation toV-loaded masoporous NiO and propane conversion enhanced over nanoscaledxV/NiO. Deep oxidation leading decreasing propene selectivity was related topolymeric V species on the NiO surface.