Analysis of multiple reactions on a bipolar electrode / V. A. Juvekar in Industrial & engineering chemistry research, Vol. 48 N° 21 (Novembre 2009)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 48 N° 21 (Novembre 2009) . - pp. 9441–9456 Titre : Analysis of multiple reactions on a bipolar electrode Type de document : texte imprimé Auteurs : V. A. Juvekar, Auteur ; Rajkumar S. Patil, Auteur ; Anand V. P. Gurumoorthy, Auteur Année de publication : 2010 Article en page(s) : pp. 9441–9456 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Bipolar electrolysis Multiple reactions Résumé : Open bipolar electrolysis is a useful technique for conducting electrolytic processes in low concentrations of electrolytes or in nonaqueous solutions. In bipolar electrolysis, both cathodic and anodic reactions occur on the same electrode. In this paper, we analyze the case of multiple reactions occurring in a bipolar manner on a single metal spheroid. Simulations are conducted for various cases involving two redox reactions. Effects of the parameters such as intensity of the imposed electric field, the Nernst potentials, exchange current densities, and transfer coefficients on the current density and the extent of coupling between the reactions have been investigated. The asymptotic cases of low and high imposed electric fields are also considered, for which simple analytic solutions are derived. Together, they cover a major operating region of practical importance. Some important insights into coupling of the reactions on the bipolar electrode have been obtained. These provide useful criteria for design of bipolar electrolytic systems. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900437n [article] Analysis of multiple reactions on a bipolar electrode [texte imprimé] / V. A. Juvekar, Auteur ; Rajkumar S. Patil, Auteur ; Anand V. P. Gurumoorthy, Auteur . - 2010 . - pp. 9441–9456. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 21 (Novembre 2009) . - pp. 9441–9456 Mots-clés : Bipolar electrolysis Multiple reactions Résumé : Open bipolar electrolysis is a useful technique for conducting electrolytic processes in low concentrations of electrolytes or in nonaqueous solutions. In bipolar electrolysis, both cathodic and anodic reactions occur on the same electrode. In this paper, we analyze the case of multiple reactions occurring in a bipolar manner on a single metal spheroid. Simulations are conducted for various cases involving two redox reactions. Effects of the parameters such as intensity of the imposed electric field, the Nernst potentials, exchange current densities, and transfer coefficients on the current density and the extent of coupling between the reactions have been investigated. The asymptotic cases of low and high imposed electric fields are also considered, for which simple analytic solutions are derived. Together, they cover a major operating region of practical importance. Some important insights into coupling of the reactions on the bipolar electrode have been obtained. These provide useful criteria for design of bipolar electrolytic systems. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900437n

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Oxidation of chloride ion on platinum electrode / Rajkumar S. Patil in Industrial & engineering chemistry research, Vol. 50 N° 23 (Décembre 2011)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 12946–12959 Titre : Oxidation of chloride ion on platinum electrode : dynamics of electrode passivation and its effect on oxidation kinetics Type de document : texte imprimé Auteurs : Rajkumar S. Patil, Auteur ; Vinay A. Juvekar, Auteur ; Vijay M. Naik, Auteur Année de publication : 2012 Article en page(s) : pp. 12946–12959 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Oxidation Ion Kinetics Résumé : Kinetics of oxidation of chloride ion is studied on both active platinum electrode and that undergoing transient passivation. Experiments are conducted in concentrated NaCl solution at rotating disk electrode. It is observed that on the active platinum electrode, oxidation is very fast, and hence the current density is controlled by the ohmic resistance of the solution. Electrode kinetics becomes important only when the electrode is passivated to a significant extent. Kinetics of chloride oxidation on the electrode undergoing passivation is modeled using the Butler–Volmer equation, in which the contribution from the ohmic resistance of the solution is incorporated. Two regimes of passivation are identified. The first is the fast regime corresponding to the formation of the platinum oxide monolayer. In this regime, the rate of passivation is first order in the concentration of the metal sites on the surface. In the slow passivation regime, the exchange current density for chloride oxidation is found to vary inversely with square root of time. This regime is modeled by considering unsteady diffusion of oxygen ions through the metal lattice. From this analysis it is concluded that the chloride oxidation current is almost totally contributed by a small fraction of the active metal sites which are continuously being regenerated as a result of diffusion of oxygen ions from the surface into the bulk of the metal. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200663a [article] Oxidation of chloride ion on platinum electrode : dynamics of electrode passivation and its effect on oxidation kinetics [texte imprimé] / Rajkumar S. Patil, Auteur ; Vinay A. Juvekar, Auteur ; Vijay M. Naik, Auteur . - 2012 . - pp. 12946–12959. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 12946–12959 Mots-clés : Oxidation Ion Kinetics Résumé : Kinetics of oxidation of chloride ion is studied on both active platinum electrode and that undergoing transient passivation. Experiments are conducted in concentrated NaCl solution at rotating disk electrode. It is observed that on the active platinum electrode, oxidation is very fast, and hence the current density is controlled by the ohmic resistance of the solution. Electrode kinetics becomes important only when the electrode is passivated to a significant extent. Kinetics of chloride oxidation on the electrode undergoing passivation is modeled using the Butler–Volmer equation, in which the contribution from the ohmic resistance of the solution is incorporated. Two regimes of passivation are identified. The first is the fast regime corresponding to the formation of the platinum oxide monolayer. In this regime, the rate of passivation is first order in the concentration of the metal sites on the surface. In the slow passivation regime, the exchange current density for chloride oxidation is found to vary inversely with square root of time. This regime is modeled by considering unsteady diffusion of oxygen ions through the metal lattice. From this analysis it is concluded that the chloride oxidation current is almost totally contributed by a small fraction of the active metal sites which are continuously being regenerated as a result of diffusion of oxygen ions from the surface into the bulk of the metal. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200663a

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