Nanosized Vanadium Oxide (V2O5/NPs): A Hetrogenous Catalyst for Direct Epoxidation of Some Alkenes Compounds

In recent year, the catalytic epoxidation of alkens are a very important area in chemistry andchemical engineering. The simplest epoxide, is ethylene epoxides, is produced by vapor-phaseoxidation of ethylene with air or oxygen over a silver catalyst, promoted by alkali metals andsupported on a non-porous form of -alumina. This process was introduced by Union Carbidein 1937 and by Shell in 1958 to replace the practice of ethylene oxide production via the chlorohydrinprocess. However, this silver catalyzed process can only by applied to olefins whichdo not process C-H allylic bonds, such as ethylene, 1,3-butadiene and styrene. For all the otherolefins, such as propane, low yields of the desired product are obtained, due to the competingoxidation of allylic C-H bonds, which leads to numerous by-products [1,2]. In this studyV2O5/NPs were prepared by a green sol-gel method according to our past project [2] and tertbutylehydroperoxid(TBHP) (1 mmol) was added to a solution of different alkenes (0.5mmol) and V2O5 /NPs (0.005 mmol) in MeOH (7 ml). The mixture was stirred at 85 °C underair condition. The reaction progress was monitored using gas chromatography and the yield ofproducts was determined by GC analysis. Assignments of products were made by comparisonwith starting materials or were identified by their IR, 1HNMR and GC-Mass spectral data.Influence of the solvent, temperature, catalyst concentration and influence of different TBHPwere studied by monitoring their reaction by GC-Mass technique see Figure 1. In general thehigh efficiency and selectivity obtained by using this catalyst.