The reduction of A 𝑧 A generates negative value of Δ𝜙 in the vicinity of the electrode as described above. The flux of A 3+ ion to the electrode surface is accelerated by the electrophoretic force, and that of A 3-ion is decreased. This is the main reason of the difference in the CV shape for A 𝑧 A (|𝑧 A | = 3).