The influence of over-stoichiometry in La2Ni0.9V0.1O4.15+δ on selective oxidative dehydrogenation of propane

Abstract

In this study, the non-stoichiometric redox compound La2Ni0.9V0.1O4.15+δ has been tested as an oxidant in selective oxidation of propane. The extent of over-stoichiometry (δ) was varied via both removing oxygen with propane in pulse experiments, as well as partial re-oxidation with oxygen. The optimal degree of over-stoichiometry (δ) has been quantified; olefins are formed whereas formation of CO2 is prevented provided that δ is below 0.03. Additionally, the structural stability of the material was tested with in situ X-ray diffraction in H2 (H2-XRD), temperature programmed reduction (TPR), thermo-gravimetric analysis (TGA), propane-pulse-experiments and re-oxidation cycles. La2Ni0.9V0.1O4.15+δ has demonstrated structure stability at 550°C and reversibility during oxidation–reduction cycles at 800°C. Therefore, La2Ni0.9V0.1O4.15+δ is considered suitable for selective oxidative dehydrogenation of propane, provided that the degree of over-stoichiometry is limited to 0.03.