Oxydehydrogenation of Propane over Vanadium Oxide Supported on Kieselguhr or MCM-41

Supported vanadium oxide (5 wt%) on either Kieselguhr or mesoporous MCM-41 was prepared using impregnation method and tested as a catalyst in propane oxidative dehydrogenation (POD). The catalyst samples were characterized using X-ray elemental analysis, Brunauer-Emmett-Teller (BET) physisorption, and Z-ray Photoelectron Spectroscopy (XPS). After impregnation, the catalyst surface area decreased compared with that of the support. More drastic decrease was observed in the case of MCM-41 (77%) than the Kieselguhr supported sample (48%). There are also different degrees of vanadium oxide-support interaction as reflected by the XPS result. Si-O binding energy of 531.5 eV was observed on MCM-41-supported sample compared with 529.5 eV for the Kieselguhr-supported sample. The catalyst tests were conducted at atmospheric pressure, with a propane to oxygen ratio of 0.7 - 3.6 and a reaction temperature of 400 - 700 °C. Oxidative dehydrogenation and combustion products were observed. Minor cracking reaction products (methane, ethane, and ethene) were also produced above 550 °C. The highest propene yield of 14% was obtained from the Kieselguhr-supported sample at 700 °C and with a C3H8/O2 ratio of 1.5.