(225a) Mass Transport at an Electrode during Electrodeposition Process

During electrodeposition process, electrochemical reactions are related in the electrode vicinity with a mixed hydrodynamic regime, natural and often forced. It is due to the reactive species transport step using diffusion, convection and electromigration. Composition heterogeneities can also induce thermo-physical properties variations due to the local chemical coupling. The modelling of these coupled phenomena using numerical method like finite differences, elements or volumes is of a great interest for both the fundamental and the applied electrochemistry. The present work is in this research field, with the goal to calculate chemical processes coupled with transport mechanic, homogeneously or heterogeneously at interfaces for the rotating cylinder electrode geometrical configuration. The numerical method used for this work is the finite volume method programmed in software like Fluidyn® with C language user defined functions. The efficiency of the use of this numerical tool in the electrochemical field has already been presented in the most popular electrochemical configuration, the confined rotating disk electrode [1]. The present work focuses its interest on the second more used electrochemical configuration, the rotating cylinder configuration, which is very used in the industrial applications. We particularly will show the hydrodynamic regime changes which occur due to the free convection flow induced during the electrodeposition process. The flow regime becomes mixed and the coupling between flow and electrochemical processes becomes strong [2]. The mass transport properties are then not yet well correlated. The complete hydrodynamic and mass transport properties in term of Sherwood number are correlated with the classical parameters and compared with success with experimentally obtained correlations and also with limiting current density measurements [3].

[1] Ph. Mandin, Th Pauporté, Ph. Fanouillère, D. Lincot, Journal of Electroanalytical Chemistry 565, 159 (2004). [2] Ph. Mandin, C. Fabian and D. Lincot, Mean and Unsteady Hydrodynamic and Mass Transport Properties at a Rotating Cylinder Electrode: From Laminar to Transitional Flow Regime, Journal of Electronalytical Chemistry, accepted june 2005 [3] Ph. Mandin, C. Fabian and D. Lincot , Numerical simulation of a Laminar Rotating Cylinder Electrode, J. Electrochem. Soc, accepted Oct. 2005