Electron levels of adsorbed ions

Adsorbed ions on metallic electrodes may change their ionic valence by donating or accepting electrons to or from the electrode they are oxidized or reduced. For example, as described in Sec. 5.7, the adsorbed proton constitutes an interfacial redox system in Eqn. 9-62  

The ratio of the concentrations of adsorbed hydrogen atoms to adsorbed protons, is derived from Eqn. 5-55 as a function of the Fermi level, ef(H /h) of the interfacial redox electrons as shown in Eqn. 9-63  

When equilibriiun is established between the electrode electrons and the interfacial redox electrons in the adsorbed protons, the Fermi level of the metallic 

If the potential is constant between the plane of adsorbed protons and the plane of electrode surface (the inner Helmholz layer), the electron level of the adsorbed protons (enH /H ) relative to the electron level of the electrode (epdo) remains unchanged with changing electrode potential (eroi  

---