Metal oxidation: A common mechanism from clusters to surfaces


The Plasma Chemistry group at the Air Force Research Laboratory has long utilized temperature dependent kinetics to look at simple ion-molecule reactions with unprecedented mechanistic detail and recently have expanded to the kinetics of cluster systems. Initial work has begun with oxidation reactions, commonly employed as a measure of cluster stability. In studies of anion clusters, neutrals, and cations a common mechanism is found that extrapolates to surface reactions as well. The lack of a dipole moment small polarizability of molecular oxygen result in very small long range potentials and weakly bound entrance complexes. Electronic transitions, such as transfer from an anion cluster forming a super-oxide increases the binding allowing further reactivity such as dissociation of the O2. The result in many systems is small kinetic barriers, early in the reaction coordinate, which control the reactivity and are related correlated to this electronic transition. Examples to be discussed include several metal anion cluster systems, as well as lanthanide neutral and cation reactions.

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Speaker Image for Albert Viggiano
Air Force Research Laboratory

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Thumbnail for Metal oxidation: A common mechanism from clusters to surfaces
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Thumbnail for Statistical modelling of temperature dependent kinetics: A simple approach often with complicated results
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