Spinels directed metal oxidation

It is known that some spinel-structured 3d-metal oxides are good catalysts for many processes involving electron transfer [12]. However, their low conductivity does not allow for the direct use in the electrode of the battery, and grafting them onto the carbon matrix is also very difficult technical problem. It was found recently that this problem could be solved indirectly, creating the spinel catalytic centers on the surface of carbon by means of adsorption of some 3d-metal complexes on the graphite surface followed by subsequent pyrolysis at certain temperatures [13,14],... 

Phase Transitions in Metal Oxide Catalysts- As alluded to above, several changes in solid structure can occur that can result in the loss of catalydcally active surface. For oxides on oxide supports, the individual solid phases may be active or a specific mixed oxide phase (such as a spinel or trirutile) may be more active than the segregated phases. Between these two extremes, many oxide catalysts are formed by monolayer epitaxy of an active surface oxide layer on a sympathetic support so that the support intimately but not directly promotes the formation of the active surface. 

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