Oxygen metal activation

However, because of the high temperature nature of this class of peroxides (10-h half-life temperatures of 133—172°C) and their extreme sensitivities to radical-induced decompositions and transition-metal activation, hydroperoxides have very limited utiUty as thermal initiators. The oxygen—hydrogen bond in hydroperoxides is weak (368-377 kJ/mol (88.0-90.1 kcal/mol) BDE) andis susceptible to attack by higher energy radicals ... 

We have already referred to the Mo/Ru/S Chevrel phases and related catalysts which have long been under investigation for their oxygen reduction properties. Reeve et al. [19] evaluated the methanol tolerance, along with oxygen reduction activity, of a range of transition metal sulfide electrocatalysts, in a liquid-feed solid-polymer-electrolyte DMFC. The catalysts were prepared in high surface area by direct synthesis onto various surface-functionalized carbon blacks. The intrinsic... 

In order to have more infoimation on the nature of the oxygen species active in partial and total oxidation we investigated the interaction of the hydrocarbons with the pre-oxidized surfaces of oxides where different types of surface oxygen species are formed. In particular we investigated p-type semiconductors like chromia, chromites and cobalt oxide C03O4. Moreover, we studied n-type metal oxides like FezOs, metal ferrites and CuObased catalysts. 

It is unknown what role is played by ligand environments in proteins and in synthetic analogues in stabilizing different species as it is also unknown which species represent active oxidants capable of transfering oxygen atoms to substrate in the enzyme systems. Moreover, it is not known how a binuclear metal active site might differ tom a mononuclear active site or if there is one type of reaction mechanism that operates in all or most of the monooxygenase enzymes or if each type of enzyme follows a different mechanism. 

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