Formation and Stability of Charged Diatomic Species

The adsorption of oxygen on an oxide surface depends on the method of pretreatment and this can be divided into three main types  

In the following paragraphs, in order to help the discussion on the formation of the oxygen species, the various oxide surfaces have been divided somewhat arbitrarily into groups. Most of the discussion refers to the 02 species since, although there is much evidence to show that this is not the only dioxygen species, there is essentially no direct information on the nature of the other oxygen species. 

Alkaline-Earth Oxides and Their Solid Solutions with Transition Metal Oxides 

Garrone et al. (163) have rationalized all these results by proposing the following mechanism for the adsorption of hydrogen and alkenes. Oxygen ions in positions of low coordination on the surface abstract protons from the adsorbed molecules to form OH c ions and a carbanion  

The formation of oxygen species on ZnO has been of interest for some time (77). Thermal activation of ZnO at about 500°C in vacuo gives an EPR signal at g = 1.96 which is thought to arise from a donor species such as Zn+ ions (755, 167-170). Adsorption of oxygen decreases the signal at 1.96, 

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