Reaction zones and elementary reactions

To quantify our reasoning, we will consider the framework of a model reaction between a diatomic gas G2 giving G anions and a metal M leading to cations with 

These methods will be developed on this reaction and we will consider some examples on how to take into account different valences. 

One of the reaction of interfaces ensures the building of the MG network to grow the layer by inward or outward development. 

We saw as a first step ehemisorption of gas on the MG layer. It is known that if this is the only phenomenon that oeeurs (see Chapter 6), it leads to an eqnilibrium where, at a given temperature, a degree of coverage of the surface is associated with the pressure of gas through an isotherm of the form  

The simplest model of the isotherm is the Langmuir isotherm, which corresponds to gas fixing on sites s of the solid having similar energy, with the free and occupied sites forming a surface solution. We will retain this model. Adsorption will thus be modeled by the dissociative elementary reaction  

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