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Quasi-reversible faradaic depolarization processes in the electrokinetics of the metal/solution interface
Jérôme F L Duval1, Jacques Buffle, Herman P van Leeuwen
1CABE (Analytical and Biophysical Environmental Chemistry), University of Geneva, Sciences II, 30 Quai E. Ansermet, Switzerland.
The Journal of Physical Chemistry. B
|March 24, 2006
Summary
Bipolar faradaic depolarization in flowing solutions with redox couples shows position-dependent electron-transfer reversibility. This significantly impacts interfacial electrokinetics, notably depressing streaming potential.
Area of Science:
- Electrochemistry
- Physical Chemistry
- Surface Science
Background:
- Bipolar faradaic depolarization at metal/solution interfaces is complex.
- Understanding its behavior under lateral flow is crucial for electrochemical systems.
Purpose of the Study:
- To quantitatively analyze bipolar faradaic depolarization with lateral solution flow.
- To investigate the influence of convective diffusion and position-dependent electron-transfer reversibility.
Main Methods:
- Numerical simulation of spatial distributions of species concentrations and electric potential.
- Analysis of nonlinear coupling between transport phenomena and electric potential.
Main Results:
- Electron-transfer reaction reversibility increases downstream, leading to asymmetric faradaic current density profiles.
- Steady-state streaming potential is significantly depressed by the bipolar faradaic process.
Conclusions:
- Lateral flow and position-dependent reversibility fundamentally alter interfacial behavior.
- The findings have substantial implications for electrokinetic phenomena in flowing electrochemical systems.
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