Physicochemical Properties and Catalytic Performances of Nanostructured V2O5 over TiO2 and γ-Al2O3 for Oxidative Dehydrogenation of Propane

Propylene is an important raw material and extensively used in the petrochemical industry. There has been a continuously growing demand for propylene in recent years around the world1–3. The majority of propylene is produced as a byproduct from processes such as steam cracking of naphtha and fluid catalytic cracking (FCC)4,5. Additional sources of propylene included dehydrogenation of propane, olefin metathesis, and natural gas-based processes. The strong demand on propylene has stimulated studies focused on development of new methods of propylene production from alternative substrates and improvement of the propylene yield from the existing processes6. Yet, an additional source of propylene was dehydrogenation of propane. This indeed was of considerable industrial importance since it represented a route economically upgrading low-cost saturated propane into the more expensive propylene7. Even though dehydrogenation of propane was more selective than the established processes, its yield of propylene was strongly influenced by the process conditions, including temperature, feed, and contact time. Byproducts obviously increased the separation costs and coke formation enforcing frequent catalyst regeneration8. The addition of O2 in terms of N2O to the reaction mixture allowed performing exothermic oxidative dehydrogenations (ODHs). The process had no thermodynamic limitations and prevented the growth of carbonaceous deposits over the catalyst9. The development of active and selective catalytic materials for the oxidative dehydrogenation of light alkanes to their corresponding alkenes has been the focal study point of many academic and industrial research groups10–19 through which, usually, the Mars–van Krevelen mechanism was assumed for the ODHP reaction. To begin with, the propane reacted with the lattice oxygen of the oxidic catalyst, such as V2O5 through which the first and then second hydrogen were abstracted from the hydrocarbon molecule. This formed two OH– groups on the surface of the catalyst coupled to produce water and desorb from the solid surface. In this venue, the propylene yield of 10 % was usually considered Physicochemical Properties and Catalytic Performances of Nanostructured V2O5 over TiO2 and γ-Al2O3 for Oxidative Dehydrogenation of Propane