Role of the Donnan potential in the formation of the electrode potential of metal-containing electron-ion exchangers

The processes of electron and ion transfer in an electron-ion exchanger (EIE) solution system were found to interact with one another via the metal counterion, a common species. A specific feature of the equilibrium electrode potential of a metal-containing EIE is its dependence not only on the activity of the metal ions in the solution but also on the activities of the other counterions. These results were used to derivative an equation relating the equilibrium electrode potential of the EIE to the Donnan potential. The Donnan potential was determined for H+ - Cu2+ equivalent exchange on a copper-containing EIE; its value explains why ultrafine copper blocks ionogenic sites.