Cyclic voltammetry in the absence of excess supporting electrolyte: The effect of analyte charge

The cyclic voltammetry of the simple electrochemically reversible reduction, A Z A + n e - ⇌ B Z B , is modelled using numerical simulations. The effect of adding different concentrations of supporting electrolyte is studied as a function of the scan rate, the diffusion coefficients of species A and B and the diffusion coefficients of the ions in the supporting electrolyte. These studies cover the following Z A / Z B redox couples: 2/1, −1/−2, 8/7, and −7/−8. The supporting information contains a table listing the minimum concentration of supporting electrolyte required to achieve fully supported voltammetry pertaining to a range of scan rates ( 10 - 1 ⩽ F ν r e 2 D A RT ⩽ 10 5 ); a wide range of charges of the electroactive species ( - 7 ⩽ Z A ⩽ 8 ) and includes both one and two electron transfer. This allows experimental conditions to be defined so that any particular Nernstian electrochemical system may be studied under diffusion-only conditions without the need for additional experiments and/or simulations.