Oxidative Dehydrogenation Of Propane For Propylene

The selective oxidation of light alkanes into valuable alkenes and organic compounds-containing oxygen has become a challenging research area in heterogeneous catalysis, among which the oxidative dehydrogenation (ODH) of propane is vital importance. Dehydrogenation of propane to propylene is highly endothermic. Due to the formation of water, oxidative dehydrogenation of propane is quite thermodynamically favorable and it can be performed at relatively low temperature. Thus it is becoming increasingly important both in academic research and industrial utilization. The influence of the addition of oxides with different oxidation state, acid-base and semiconduction on the properties of the typical p-type semiconductor NiO is investigated for propane ODH at low temperature. NixV1..xOy (X=1 to 0) series catalysts are prepared and characterized by BET, XRD, H2-TPR, 02-TPD-MS, FT-IR, XPS, in situ electrical conductivity and surface acid-base measurements. Their catalytic performance for ODH of propane to propylene is originally reported. The formation, existence of active oxygen species of Ni-V-O catalysts and their catalytic behaviors to ODH of propane are mainly investigated. It can be found that the catalysts with both NiO and Ni3V2O8 show low temperature catalytic properties for propane ODH. The ratio and synergetic effect between NiO and Ni3V2O8 in Ni-V-O catalysts play important role in the control of acid-base of the catalysts, the formation Abstract III of mobile oxygen and the activity of oxygen species. 20% of propane conversion and 52% of propene selectivity on Ni0.9V0.1O~ catalysts are obtained at 425C and it can be observed that the active oxygen species are mobile oxygen ones (e.g. 0, 02 or 022) which are neither lattice oxygen nor adsorption oxygen species. n-type semiconductor LaVO4 has been employed as parent catalyst and its properties such as active oxygen species and catalytic activity could be modified by the substitution of La3~ with rare earth cations and the addition of different kinds of oxide promoters. A good correlation between mobile oxygen species and propane ODH behavior of the catalysts is observed.