Transition metal salts/complexes with hydrogen peroxide

Transition metals have the ability to form a complex with an electron donor. In this complex, the outermost set of five stable d electron orbitals of the transition metal is partially filled. When transition metal salts, such as ferrous sulfate, are combined with hydrogen peroxide, the resulting oxidation power is known as Fenton s reagent. Instead of forming a complex with hydrogen peroxide, the ferrous ion loses one electron to the peroxide bond of hydrogen peroxide. As a result, a hydroxyl radical and a hydroxide ion are formed. 

The oxidation of hydrocarbons by molecular oxygen in the absence of metal complexes has been discussed in Chapter II. The oxidation of hydrocarbons with molecular oxygen, as well as with donors of an oxygen atom (hydrogen peroxide, alkyl hydroperoxides and some other compounds), is a very important field since many industrial processes are based on these reactions [1], In many cases, chain radical non-catalyzed autoxidation of samrated hydrocarbons is not very selective and the yields of valuable products are often low. The use of salts and complexes of transition metals creates great possibilities for solving problems of selective oxidation, as has been demonstrated for a number of important processes. 

The most widely used industrial routes to propylene oxide (PO) are based on the chlorohydrin process or hydroperoxide methods. Much attention has also been directed to processes performed in the presence of hydrogen peroxide in the liquid phase with a TS-1 molecular sieve as the catalyst, iron complexes accommodated in amorphous SBA-15 and MCM-41 modified with alkaline metal salts, and SBA-3 mesoporous molecular sieves doped with transition metal ions (Fe, V, Nb, and Ta). 

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