Preparation, Characterization Of Mesoporous V₂O₅-SiO₂ Supported CeO₂ And Au Catalysts And Studies On Their Catalytic Properties For Oxidative Dehydrogenation Of Propane To Propylene

In recent years, the dehydrogenation provides a promising alternative route for the efficient production of light alkenes from the corresponding alkenes, which are abundant and low cost raw materials. The catalytic dehydrogenation of propane to is of increasing importance due to the growing demand for propene, which is an important resource in the production of polypropene, polyacrylonitrile, acrolein, and acrylic acid. The oxidative dehydrogenation(ODH) of propane is attractive because it is an exothermic and nonthermo dynamically limited reaction. At low temperature, propane can convert on the catalysts that can remain high activity even when carbon deposit. However, the propene selectivity of the catalytic reaction remains an unsolved problem owing to over oxidation of propene. The aim of researchers is to prepare catalysts that can improve both the conversion of propane and the selectivity of propene.In this dissertation, the mesoporous V2O5-Si O2 as a carrier, then different cerium and gold loading x%Ce O2/V2O5-Si O2 and x%Au/V2O5-Si O2 catalysts were prepared. Then the catalysts were characterized by XRD, N2-sorption, H2-TPR, DRS UV-Vis, XPS, and TEM measurement. The catalytic performances for the oxidative dehydrogenation of propane were investigated.1. The mesoporous V2O5-Si O2 with high surface area were prepared by different methods to investigate the influences of preparation method、source of vanadium and the ratio of V/Si. The experimental results show that the gold loading also affects the catalytic performance. The VAA catalysts were prepared by sol-gol method, with 8%the vanadium contents, exhibit the good catalytic properties of oxidative dehydrogenation of propane, with highest selectivity to propene 68.57 %, at 500 °C.2. The x%Ce O2/V2O5-Si O2 catalysts with different Ce O2 contents were prepared by impregnation methods. The experimental results show that the optimistic catalyst was 6%Ce O2/V2O5-Si O2 with highest conversion of propane of 27.9% and highest selectivity to propene of 25.7% at 500 °C.3. The x%Au/V2O5-Si O2 catalysts with different gold contents were prepared by deposition- precipitation(DP) method, the gold loading reach 3%, the gold catalysts exhibit the good catalytic properties of oxidative dehydrogenation of propane. The optimistic catalyst was 1%Au/V2O5-Si O2 with highest propene yield of 10.52 %, at 600 °C.