Studies On The Catalytic Properties Of Mesoporous V₂O₅/Ce_xZr_1-xO₂ Catalysts For The Oxidative Dehydrogenation Of Propane To Propylene

In recent years, due to the rapid development of downstream products of propylene, polypropylene, acrylonitrile acrolein and acrylic acid, this has greatly promoted the rapid growth of the global demand for propylene. The dehydrogenation of propane causes a great of interest because the resources are cheap and rich. But the dehydrogenation for propane is endothermic reaction, high temperature is needed in this reaction for enhancing conversion of propane. The reducing of selectivity of propylene and deactivation of catalysts exist because of high temperature causing cracking reaction. Another,the oxidative dehydrogenation of propane is exothermic reaction and the reaction temperature is low. The catalyst do not lose activity because of coke.But propane and propylene are easy happening the deep oxidation, the selectivity of propylene is low. It is the purpose of researchers that the ideal catalyst of ODHP and DHP is developed. Because of above reasons, the research of this paper has two part.1、CTAB as structure directing agent, CexZr1-x O2 catalysts are prepared with one step method and the catalysts are mesoporous. Catalysts are character with XRD, BET, TEM, H2-TPR,TG-DTA, DR UV–vis and XPS.The performances of ODHP and DHP were also studied.2、We prepared a series of nanometer x V2O5/ Cex Zr1-x O2 catalysts with impregnation method and we character these catalysts. We studied the radio of Ce and Gr, the radio of V2O5 and Cex Zr1-x O2 had influence to ODHP. The results showed nanometer x V2O5/ Cex Zr1-x O2 catalysts had good activity. The results of H2-TPR, Raman, DR UV-vis and XPS showed the radio of Ce and Gr had influence to the amount of V on surface. Contacting with results of activity test, polymerization V on surface had good at ODHP. 4VCe2Zr8 had best activity of IDHP.3 、 We studied performances for ODHP and ODHP under CO2of4VCe2Zr8 catalyst. The in situ conductivity tests were conducted. The results showed catalysts were n-type semiconductor and 4VCe2Zr8 catalysts had best activity. It was same with results of activity test.