The kinetics of the ferrous/ferric and ferro/ferricyanide reactions at platinum and gold electrodes

Angell, David; Dickinson, T.

doi:10.1016/s0022-0728(72)80294-8

Cited by 161 publications

(75 citation statements)

References 23 publications

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“…Gold disk microelectrodes of different radii (r 0 ¼ 12. , which are in line with previous results in the literature (see [28,29]). We have also determined the formal potential of FeCl 3 from current reversal chronopotentiometric measures at a gold disk electrode of r 0 ¼ 5 Â 10 À2 cm by following the procedure indicated in [30], and obtaining the value E8' ¼ 0.508 AE 0.001 V (vs. Ag/AgCl), KCl 1.0 M, which is in line with results in [31].…”

Section: Methodssupporting

confidence: 93%

“…On the other hand, we have used Equations 2.3 -2.4 in Table 2 for the dI/dE vs. E curves to obtain the charge transfer coefficient and the heterogeneous rate constant of the Fe 3þ reduction in HClO 4 media, once the values of the diffusion coefficient of oxidized species and the formal potential of the electroactive couple are known (see experimental section). From equations in Table 2 it can be deduced that, [29]. For the determination of k8' we have used a microdisk and we have applied Equations 2.3 -2.4 of Table 2 corresponding to a microsphere supposing that r 0,sphere % (2/p)r 0,disk .…”

Section: Resultsmentioning

confidence: 99%

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Steady State Reciprocal Derivative Chronopotentiometry with Programmed Currents at Microelectrodes

2005

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Equations corresponding to the application of Reciprocal Derivative Chronopotentiometry with programmed currents to spherical and disk microelectrodes under steady state conditions have been deduced. Traditional stationary dt/dE vs. E curves for a current time function of the form I(t) ¼ I 0 t u , u > 0, and the new dI/dE vs. E curves, which do not depend on the particular characteristics of the applied programmed current I(t) are shown for any degree of reversibility of the electrode process. The evolution from transient to steady state for both derivative techniques has been analyzed. Criteria for characterizing reversible and totally irreversible stationary derivative curves, together with easy methods for determining thermodynamic and kinetic parameters of the charge transfer process from the measure of peak parameters are proposed. The validity of the theoretical predictions has been experimentally tested with hexachloroiridate(IV) reversible oxidation and with iron(III) irreversible reduction in aqueous media.

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Section: Methodssupporting

confidence: 93%

Section: Resultsmentioning

confidence: 99%

Steady State Reciprocal Derivative Chronopotentiometry with Programmed Currents at Microelectrodes

2005

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“…The electrode acts as the source or sink of electrons for the redox reaction and is supposed to be inert. The reduction of ferricyanide to ferrocyanide at a platinum electrode is described in the literature [2][3][4][5] as an example of such a mechanism, i.e. FeðCNÞ 3À 6 þ e À $ FeðCNÞ 4À 6 ð1Þ Because no complex mechanism is expected to take place, this system is chosen here to evaluate the methodology that was set-up in the previous part [1].…”

Section: Introductionmentioning

confidence: 99%

Extraction of a quantitative reaction mechanism from linear sweep voltammograms obtained on a rotating disk electrode. Part II: Application to the redoxcouple

Tourwe

Breugelmans

Pintelon

et al. 2007

Journal of Electroanalytical Chemistry

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“…After 30 min of anodic polarization two new vibrational bands appear at 250 and 380 cm -1 which are associated to the iron hydroxide of lepidocrocite (γ-FeOOH). This stable corrosion product is formed from the reaction of iron ions in solution with dissolved oxygen and water molecules [26,27]. Figure 3 shows the cathodic polarization curves of the steel in sulfate medium under aerated conditions and at different rates of electrode rotation.…”

Section: Anodic Behavior Of Carbon Steel In Sulfate Aerated Mediummentioning

confidence: 99%

“…Figure 4 shows the graph of I L vs. ω 1/2 which follows the behavior described by the Levich equation, Eq. ) [27], "C*" is the concentration of the electroactive species in the bulk electrolyte (mol cm -3 ) and "ω" is the rotation speed in rad s -1 . According to Eq.…”

Section: Anodic Behavior Of Carbon Steel In Sulfate Aerated Mediummentioning

confidence: 99%

Effect of aeration on Tafelian behavior of the carbon steel corrosion in acid sulfate medium

Sepúlveda

Vásquez

Gutiérrez

2017

Rev. Fac. Ing. Univ. Antioquia

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This study presents a corrosion analysis of carbon steel by electrochemical polarization tests on a rotating disk electrode at several aeration and hydrodynamic conditions in solution 0.2 mol L -1 K 2 SO 4 at pH 3. The reactions involved in the dissolution of the steel are analyzed by studying the Tafel regions of the polarization curves, confirming that the dissolved oxygen plays a predominant role in the corrosion of the metal. The corrosion rate was 35 times higher in natural aeration conditions than in the deaerated medium. Under natural aeration conditions, it is not possible to make a simple analysis of the corrosion of the steel from the extrapolation of the Tafel slopes since such slopes were not well defined due to the formation of rust in the anodic region and the influence of mass transport in the cathodic region. At cathodic polarization potentials and with natural aeration, there is an increase in polarization currents with respect to the deaerated system and the oxygen reduction reaction is controlled by the mass transport. Under deaerated conditions and at intermediate polarization potentials, there is a change in the dissolution mechanism of the steel. At high overpotential, the rate of dissolution of the steel tends to be equal in both systems, aerated and deaerated because the corrosion of the metal is controlled by the diffusion of species through corrosion products film. RESUMEN:Este estudio presenta un análisis de corrosión del acero al carbono mediante pruebas de polarización electroquímica en un electrodo de disco rotatorio en varias condiciones de aireación e hidrodinámicas en solución 0,2 mol L -1 K 2 SO 4 a pH 3. Las reacciones implicadas en la disolución del acero se analizan estudiando Tafel regiones de las curvas de polarización, lo que confirma que el oxígeno disuelto desempeña un papel predominante en la corrosión del metal. La velocidad de corrosión fue 35 veces mayor en condiciones de aireación natural que en el medio desaireado. Bajo condiciones de aireación natural no es posible realizar un análisis simple de la corrosión del acero a partir de la extrapolación de las pendientes de Tafel, ya que tales pendientes no están bien definidas debido a la formación de óxido en la región anódica y a la influencia del transporte de masa en la región catódica. En los potenciales de polarización catódica y con aireación natural, hay un aumento en las corrientes de polarización con respecto al sistema desaireado y la reacción de reducción de oxígeno es controlada por el transporte de masa. Bajo condiciones desaireadas y en potenciales de polarización intermedios, hay un cambio en el mecanismo de disolución del acero. A altos sobrepotenciales, la velocidad de disolución del acero tiende a ser igual en ambos sistemas (aireado y desaireado), porque la corrosión del metal es controlada por la difusión de especies a través de la película de productos de corrosión.

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The kinetics of the ferrous/ferric and ferro/ferricyanide reactions at platinum and gold electrodes

Cited by 161 publications

References 23 publications

Steady State Reciprocal Derivative Chronopotentiometry with Programmed Currents at Microelectrodes

Steady State Reciprocal Derivative Chronopotentiometry with Programmed Currents at Microelectrodes

Extraction of a quantitative reaction mechanism from linear sweep voltammograms obtained on a rotating disk electrode. Part II: Application to the redoxcouple

Effect of aeration on Tafelian behavior of the carbon steel corrosion in acid sulfate medium

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