Catalytic mechanism in cyclic voltammetry at disc electrodes: an analytical solution

Area of Science:

• Electrochemistry
• Chemical Kinetics
• Analytical Chemistry

Background:

• Catalytic processes are vital in electrochemistry, particularly for chemical sensing.
• Previous theoretical treatments for catalytic cyclic voltammetry at disc electrodes relied on complex numerical methods.
• A lack of analytical expressions hindered understanding of transient responses in these systems.

Purpose of the Study:

• To develop an analytical solution for cyclic voltammetry involving catalytic regeneration at disc electrodes.
• To provide a mathematical framework for systems with two-dimensional mass transport and non-uniform surface gradients.
• To enable accurate characterization of catalytic electrochemical reactions.

Main Methods:

• Development of an analytical solution using the induction principle.
• Application of the superposition principle for electrode geometry independence.
• Mathematical derivation of an equation for transient responses in catalytic cyclic voltammetry.

Main Results:

• An analytical expression for the transient response of catalytic cyclic voltammetry at disc electrodes was derived.
• The derived equation is valid for any electrode size and catalytic reaction kinetics.
• The theory was successfully applied to the electrocatalytic Fenton reaction.

Conclusions:

• The developed analytical solution fills a critical gap in the theory of cyclic voltammetry with catalytic regeneration.
• The findings offer a powerful tool for analyzing catalytic electrochemical systems and chemical sensors.
• The study provides a method to determine rate constants, exemplified by the Fenton reaction analysis.