Dear Dr. Turan Ilhan,

- Electrode potential, E, in chemistry or electrochemistry, according to an IUPAC definition, is the electromotive force of a cell built of two electrodes:

on the left-hand side of the cell diagram is the standard hydrogen electrode (SHE), and

on the right-hand side is the electrode in question.

The SHE is defined to have a potential of 0 V, so the signed cell potential from the above setup is

Ecell = Eright − Eleft (SHE) = Eelectrode - 0 V = Eelectrode.

The SHE (Standard Hydrogen Electrode) is the anode (left) and an electrode is a cathode (right)

An electrode potential is strictly the potential difference developed at the interface between the electrode and the solution. It is common, for instance, to speak of the electrode potential of the M+/M redox couple. These potential differences are measured relative to the potential difference developed at a suitable reference electrode, which is conventionally the SHE; that is to say, E(M+/M) = (VM - VM+) - (VH2 - VH+).

-Corrosion potential is a mixed potential (also an open-circuit potential or rest potential) at which the rate of anodic dissolution of the electrode equals the rate of cathodic reactions and there is no net current flowing in or out of the electrode. The corrosion potential is the potential a sample has, when no external current is applied. A current can still flow to enable two reactions, one oxidation and one reduction, at the sample. For example a steel sample in contact with an acid solution will oxidize (depending on the steel composition) and protons will be reduced at the surface. If you connect a voltmeter and a reference electrode, the measured potential is the corrosion potential of the steel-proton reaction.

For more details, please see the following, interesting PalmSens technical note at:

https://www.palmsenscorrosion.com/knowledgebase/corrosion-potential/

Best regards, Pierluigi Traverso

Dear Dr. Turan Ilhan,

- Electrode potential, E, in chemistry or electrochemistry, according to an IUPAC definition, is the electromotive force of a cell built of two electrodes:

on the left-hand side of the cell diagram is the standard hydrogen electrode (SHE), and

on the right-hand side is the electrode in question.

The SHE is defined to have a potential of 0 V, so the signed cell potential from the above setup is

Ecell = Eright − Eleft (SHE) = Eelectrode - 0 V = Eelectrode.

The SHE (Standard Hydrogen Electrode) is the anode (left) and an electrode is a cathode (right)

An electrode potential is strictly the potential difference developed at the interface between the electrode and the solution. It is common, for instance, to speak of the electrode potential of the M+/M redox couple. These potential differences are measured relative to the potential difference developed at a suitable reference electrode, which is conventionally the SHE; that is to say, E(M+/M) = (VM - VM+) - (VH2 - VH+).

-Corrosion potential is a mixed potential (also an open-circuit potential or rest potential) at which the rate of anodic dissolution of the electrode equals the rate of cathodic reactions and there is no net current flowing in or out of the electrode. The corrosion potential is the potential a sample has, when no external current is applied. A current can still flow to enable two reactions, one oxidation and one reduction, at the sample. For example a steel sample in contact with an acid solution will oxidize (depending on the steel composition) and protons will be reduced at the surface. If you connect a voltmeter and a reference electrode, the measured potential is the corrosion potential of the steel-proton reaction.

For more details, please see the following, interesting PalmSens technical note at:

https://www.palmsenscorrosion.com/knowledgebase/corrosion-potential/

Best regards, Pierluigi Traverso

Dear Pierluigi Traverso thank you for detailed answer