LE, T.D.; LASSEUX, Didier; NGUYEN, X.P.; VIGNOLES, G.; MANO, Nicolas; KUHN, A.

doi:10.1016/j.ces.2017.07.039

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Ce document a été publié dans

Chemical Engineering Science. 2017-07-25, vol. 173, p. pp. 153-167

Elsevier

Résumé en anglais

A multi-scale model of diffusion/reaction at play in a porous electrode is developed and solutions to the physico-electro-chemical coupled problem are provided. This represents a key step to progress in the optimization of new efficient and innovative micro-electro-devices that needs to be addressed from a chemical engineering point of view. The pore-scale model based on Fickian diffusion in the porous medium and Nernstian layer and the electrochemical reaction governed by the Buttler-Volmer equation isupscaled using volume averaging to obtain a macroscopic model that describes the process on an effective equivalent medium. The validity and accuracy of the macroscopic model is successfully checked through the comparison with direct numerical simulations of the initial microscale model for amperometry tests. Predictions obtained from the upscaled model on the current intensity versus the scanning potential during voltammetry reveal to be in very good agreement with experimental results reported in the literature. These results show the capability of the macroscopic model to analyze the behavior of the porous electrode. In particular, it provides an efficient tool to study the dependence of the current intensity on the microstructure of the porous material and on the electrochemical parameters with the perspective of optimizing the electrode efficiency.< Réduire

Mots clés en anglais

Porous electrode

Diffusion

Heterogeneous reaction

Volume averaging method

URI

https://oskar-bordeaux.fr/handle/20.500.12278/77291

DOI

http://dx.doi.org/10.1016/j.ces.2017.07.039

Project ANR

Initiative d'excellence de l'Université de Bordeaux - ANR-10-IDEX-0003

Origine

Importé de hal

Unités de recherche

Institut de Mécanique et d’Ingénierie de Bordeaux (I2M) - UMR 5295