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Valentin Mirceski - One of the best experts on this subject based on the ideXlab platform.

  • new aspects of the electrochemical catalytic ec mechanism in square wave voltammetry
    Electrochimica Acta, 2015
    Co-Authors: Rubin Gulaboski, Valentin Mirceski
    Abstract:

    Abstract Several new theoretical aspects of the electrocatalytic (regenerative) EC’ mechanism under conditions of square-wave (SWV) and staircase cyclic voltammetry (SCV) are presented. Elaborating the effect of the rate of the catalytic Reaction in the diffusion-controlled catalytic mechanism (diffusional EC’ mechanism) and surface catalytic mechanism (surface EC’ mechanism), we refer to several phenomena related to the shift of the position and the half-peak width of the net peak in square-wave voltammetry (SWV). If the rate of the catalytic Reaction is much higher than the kinetics of the Electrode Reaction, a linear dependence between the peak potential of the simulated net SWV peaks and the logarithm of the catalytic parameter can be observed. The intercept of that linear dependence is a function of the kinetics of the Electrode Reaction. Based on this finding, we propose a new methodology to determine the Electrode kinetics rate constant. The proposed approach relies on the variation of the concentration of the regenerative reagent. To the best of our knowledge, this is one of very few voltammetric approaches for Electrode kinetic measurements not based on the time or potential variation in the experimental analyzes. In addition, we present a brief analysis of the catalytic mechanism under conditions of staircase cyclic voltammetry in order to emphasize the main differences between SCV and SWV.

  • new approach to Electrode kinetic measurements in square wave voltammetry amplitude based quasireversible maximum
    Analytical Chemistry, 2013
    Co-Authors: Valentin Mirceski, Eduardo Laborda, Dariusz Guziejewski, Richard G. Compton
    Abstract:

    The influence of the potential pulse height of square-wave voltammetry (SWV) (i.e., the SW amplitude) is studied for a variety of quasireversible Electrode mechanisms, including a simple solution-phase Electrode Reaction at a planar or spherical Electrode, a solution phase Electrode Reaction coupled with a reversible follow-up chemical Reaction, and a diffusionless surface confined Electrode Reaction. The Electrode kinetics of all the Electrode mechanisms depends critically on the SW amplitude, and the quasireversible kinetic region is a function of both frequency-related Electrode kinetic parameters and the SW amplitude. Thus, a novel methodology for Electrode kinetics measurements is proposed by altering the SW amplitude only, at a fixed frequency of the SW potential modulation, that is, at a constant scan rate of the voltammetric experiment. Electrode kinetic measurements at a constant SW frequency are of exceptional importance especially when complex Electrode mechanisms are studied, which depend on s...

  • new approach to Electrode kinetic measurements in square wave voltammetry amplitude based quasireversible maximum
    Analytical Chemistry, 2013
    Co-Authors: Valentin Mirceski, Eduardo Laborda, Dariusz Guziejewski, Richard G. Compton
    Abstract:

    The influence of the potential pulse height of square-wave voltammetry (SWV) (i.e., the SW amplitude) is studied for a variety of quasireversible Electrode mechanisms, including a simple solution-phase Electrode Reaction at a planar or spherical Electrode, a solution phase Electrode Reaction coupled with a reversible follow-up chemical Reaction, and a diffusionless surface confined Electrode Reaction. The Electrode kinetics of all the Electrode mechanisms depends critically on the SW amplitude, and the quasireversible kinetic region is a function of both frequency-related Electrode kinetic parameters and the SW amplitude. Thus, a novel methodology for Electrode kinetics measurements is proposed by altering the SW amplitude only, at a fixed frequency of the SW potential modulation, that is, at a constant scan rate of the voltammetric experiment. Electrode kinetic measurements at a constant SW frequency are of exceptional importance especially when complex Electrode mechanisms are studied, which depend on several frequency-related kinetic parameters. The Electrode kinetic measurements are based on a novel feature termed the "amplitude-based quasireversible maximum", manifested as a parabolic dependence of the amplitude-normalized net SW peak current versus the SW amplitude. The position of the amplitude-based quasireversible maximum depends on the standard rate constant of the Electrode Reaction, enabling estimation of this important kinetic parameter in a simple and fast procedure. The novel quasireversible maximum is attributed to all studied Electrode mechanisms, implying that it is a general feature of most Electrode mechanisms under conditions of SWV.

  • theoretical treatment of a cathodic stripping mechanism of an insoluble salt coupled with a chemical Reaction in conditions of square wave voltammetry application to 6 mercaptopurine 9 d riboside in the presence of ni ii
    Electroanalysis, 2011
    Co-Authors: Valentin Mirceski, Dariusz Guziejewski, Witold Ciesielski
    Abstract:

    Cathodic stripping mechanism of an insoluble salt coupled with a homogenous chemical Reaction is considered both theoretically and experimentally under conditions of square-wave voltammetry. For the mercury Electrode in aqueous solution, the Electrode Reaction is described as L(aq) + Hg(l) = HgL(s) + 2e

  • electrochemical study of the pesticide methidathion at a mercury Electrode under cathodic stripping mode
    Croatica Chemica Acta, 2010
    Co-Authors: Valentin Mirceski, Dariusz Guziejewski, Slawomira Skrzypek, Witold Ciesielski
    Abstract:

    Methidathion, a non-systemic organophosphorous insecticide and acaricide is studied at the hanging mercury drop Electrode under cathodic stripping mode by means of cyclic and square-wave voltammetry (SWV). Its Electrode Reaction is analyzed in the light of recent theory of cathodic stripping processes of insoluble salts of SWV. Its complex Electrode mechanism is described by an Electrode Reaction of a second order, complicated by adsorption of methidathion molecules on the Electrode surface involving lateral interactions between each other. Moreover, under specific experimental conditions the Electrode mechanism can be additionally complicated by multilayer formation on the Electrode surface, as well as by a chemical transformation following the cathodic stripping process of the methidathion-mercury salt. Following the mechanistic study of the Electrode Reaction, a method for quantitative determination of methidathion is proposed applying SWV.

Richard G. Compton - One of the best experts on this subject based on the ideXlab platform.

  • two electron two proton oxidation of catechol kinetics and apparent catalysis
    Journal of Physical Chemistry C, 2015
    Co-Authors: Qian Li, Christopher Batchelormcauley, Richard G. Compton
    Abstract:

    The study of proton-coupled electron transfer Reactions is of great current interest. In this work, the catechol redox process was studied voltammetrically in the pH range from 1.0 to 14.0 using a glassy carbon Electrode. Analysis of the peak potentials and currents together with Tafel analysis allowed the inference of the likely transition states and Electrode Reaction mechanism. Modification of the glassy carbon Electrode surface with sparse coverages of alumina particles was shown to lead to strong apparent catalysis of the catechol redox process at low pH. A possible mechanism for this is proposed.

  • new approach to Electrode kinetic measurements in square wave voltammetry amplitude based quasireversible maximum
    Analytical Chemistry, 2013
    Co-Authors: Valentin Mirceski, Eduardo Laborda, Dariusz Guziejewski, Richard G. Compton
    Abstract:

    The influence of the potential pulse height of square-wave voltammetry (SWV) (i.e., the SW amplitude) is studied for a variety of quasireversible Electrode mechanisms, including a simple solution-phase Electrode Reaction at a planar or spherical Electrode, a solution phase Electrode Reaction coupled with a reversible follow-up chemical Reaction, and a diffusionless surface confined Electrode Reaction. The Electrode kinetics of all the Electrode mechanisms depends critically on the SW amplitude, and the quasireversible kinetic region is a function of both frequency-related Electrode kinetic parameters and the SW amplitude. Thus, a novel methodology for Electrode kinetics measurements is proposed by altering the SW amplitude only, at a fixed frequency of the SW potential modulation, that is, at a constant scan rate of the voltammetric experiment. Electrode kinetic measurements at a constant SW frequency are of exceptional importance especially when complex Electrode mechanisms are studied, which depend on s...

  • new approach to Electrode kinetic measurements in square wave voltammetry amplitude based quasireversible maximum
    Analytical Chemistry, 2013
    Co-Authors: Valentin Mirceski, Eduardo Laborda, Dariusz Guziejewski, Richard G. Compton
    Abstract:

    The influence of the potential pulse height of square-wave voltammetry (SWV) (i.e., the SW amplitude) is studied for a variety of quasireversible Electrode mechanisms, including a simple solution-phase Electrode Reaction at a planar or spherical Electrode, a solution phase Electrode Reaction coupled with a reversible follow-up chemical Reaction, and a diffusionless surface confined Electrode Reaction. The Electrode kinetics of all the Electrode mechanisms depends critically on the SW amplitude, and the quasireversible kinetic region is a function of both frequency-related Electrode kinetic parameters and the SW amplitude. Thus, a novel methodology for Electrode kinetics measurements is proposed by altering the SW amplitude only, at a fixed frequency of the SW potential modulation, that is, at a constant scan rate of the voltammetric experiment. Electrode kinetic measurements at a constant SW frequency are of exceptional importance especially when complex Electrode mechanisms are studied, which depend on several frequency-related kinetic parameters. The Electrode kinetic measurements are based on a novel feature termed the "amplitude-based quasireversible maximum", manifested as a parabolic dependence of the amplitude-normalized net SW peak current versus the SW amplitude. The position of the amplitude-based quasireversible maximum depends on the standard rate constant of the Electrode Reaction, enabling estimation of this important kinetic parameter in a simple and fast procedure. The novel quasireversible maximum is attributed to all studied Electrode mechanisms, implying that it is a general feature of most Electrode mechanisms under conditions of SWV.

Katsuhiko Hirano - One of the best experts on this subject based on the ideXlab platform.

  • kinetics of the Electrode Reaction at the h sub 2 h sub 2 o porous pt stabilized zirconia interface
    Journal of The Electrochemical Society, 1994
    Co-Authors: Junichiro Mizusaki, Hiroaki Tagawa, Kensuke Isobe, Motoaki Tajika, Ikumasa Koshiro, Hideki Maruyama, Katsuhiko Hirano
    Abstract:

    Recently, much interest has been focused on the Electrode Reaction at the interface of porous Pt/stabilized zirconia in compound-gas mixtures such as CO-CO[sub 2], H[sub 2]-H[sub 2]O, CH[sub 4]-H[sub 2]O, and others, because this Reaction is important as a model of the Electrode Reaction in zirconia cells either for sensors, fuel cells, water electrolyzer, or other applications. To elucidate the mechanism of the Electrode Reaction at the interface of H[sub 2]-H[sub 2]O porous Pt/stabilized zirconia, measurements were made on the Electrode interface conductivity, [sigma][sub E], and the steady-state polarization current, I, as a function of H[sub 2] partial pressure, p[sub H2], and H[sub 2]O partial pressure, p[sub H2O], up to 800 C. The rate of the Electrode Reaction at 700 to 800 C in H[sub 2]-H[sub 2]O atmospheres is faster than that in CO-CO[sub 2] and slower than that in O[sub 2] rich atmospheres by 1 to 2 orders of magnitude. The rate-determining Reaction process was the exchange of adsorbed OH radicals between the Pt- and the stabilized zirconia-surface at the triple-phase boundary (TPB) of gas/Pt/stabilized zirconia.

  • kinetics of the Electrode Reaction at the h 2 h 2 o porous pt stabilized zirconia interface
    Journal of The Electrochemical Society, 1994
    Co-Authors: Junichiro Mizusaki, Hiroaki Tagawa, Kensuke Isobe, Motoaki Tajika, Ikumasa Koshiro, Hideki Maruyama, Katsuhiko Hirano
    Abstract:

    Recently, much interest has been focused on the Electrode Reaction at the interface of porous Pt/stabilized zirconia in compound-gas mixtures such as CO-CO[sub 2], H[sub 2]-H[sub 2]O, CH[sub 4]-H[sub 2]O, and others, because this Reaction is important as a model of the Electrode Reaction in zirconia cells either for sensors, fuel cells, water electrolyzer, or other applications. To elucidate the mechanism of the Electrode Reaction at the interface of H[sub 2]-H[sub 2]O porous Pt/stabilized zirconia, measurements were made on the Electrode interface conductivity, [sigma][sub E], and the steady-state polarization current, I, as a function of H[sub 2] partial pressure, p[sub H2], and H[sub 2]O partial pressure, p[sub H2O], up to 800 C. The rate of the Electrode Reaction at 700 to 800 C in H[sub 2]-H[sub 2]O atmospheres is faster than that in CO-CO[sub 2] and slower than that in O[sub 2] rich atmospheres by 1 to 2 orders of magnitude. The rate-determining Reaction process was the exchange of adsorbed OH radicals between the Pt- and the stabilized zirconia-surface at the triple-phase boundary (TPB) of gas/Pt/stabilized zirconia.

Dariusz Guziejewski - One of the best experts on this subject based on the ideXlab platform.

  • new approach to Electrode kinetic measurements in square wave voltammetry amplitude based quasireversible maximum
    Analytical Chemistry, 2013
    Co-Authors: Valentin Mirceski, Eduardo Laborda, Dariusz Guziejewski, Richard G. Compton
    Abstract:

    The influence of the potential pulse height of square-wave voltammetry (SWV) (i.e., the SW amplitude) is studied for a variety of quasireversible Electrode mechanisms, including a simple solution-phase Electrode Reaction at a planar or spherical Electrode, a solution phase Electrode Reaction coupled with a reversible follow-up chemical Reaction, and a diffusionless surface confined Electrode Reaction. The Electrode kinetics of all the Electrode mechanisms depends critically on the SW amplitude, and the quasireversible kinetic region is a function of both frequency-related Electrode kinetic parameters and the SW amplitude. Thus, a novel methodology for Electrode kinetics measurements is proposed by altering the SW amplitude only, at a fixed frequency of the SW potential modulation, that is, at a constant scan rate of the voltammetric experiment. Electrode kinetic measurements at a constant SW frequency are of exceptional importance especially when complex Electrode mechanisms are studied, which depend on s...

  • new approach to Electrode kinetic measurements in square wave voltammetry amplitude based quasireversible maximum
    Analytical Chemistry, 2013
    Co-Authors: Valentin Mirceski, Eduardo Laborda, Dariusz Guziejewski, Richard G. Compton
    Abstract:

    The influence of the potential pulse height of square-wave voltammetry (SWV) (i.e., the SW amplitude) is studied for a variety of quasireversible Electrode mechanisms, including a simple solution-phase Electrode Reaction at a planar or spherical Electrode, a solution phase Electrode Reaction coupled with a reversible follow-up chemical Reaction, and a diffusionless surface confined Electrode Reaction. The Electrode kinetics of all the Electrode mechanisms depends critically on the SW amplitude, and the quasireversible kinetic region is a function of both frequency-related Electrode kinetic parameters and the SW amplitude. Thus, a novel methodology for Electrode kinetics measurements is proposed by altering the SW amplitude only, at a fixed frequency of the SW potential modulation, that is, at a constant scan rate of the voltammetric experiment. Electrode kinetic measurements at a constant SW frequency are of exceptional importance especially when complex Electrode mechanisms are studied, which depend on several frequency-related kinetic parameters. The Electrode kinetic measurements are based on a novel feature termed the "amplitude-based quasireversible maximum", manifested as a parabolic dependence of the amplitude-normalized net SW peak current versus the SW amplitude. The position of the amplitude-based quasireversible maximum depends on the standard rate constant of the Electrode Reaction, enabling estimation of this important kinetic parameter in a simple and fast procedure. The novel quasireversible maximum is attributed to all studied Electrode mechanisms, implying that it is a general feature of most Electrode mechanisms under conditions of SWV.

  • theoretical treatment of a cathodic stripping mechanism of an insoluble salt coupled with a chemical Reaction in conditions of square wave voltammetry application to 6 mercaptopurine 9 d riboside in the presence of ni ii
    Electroanalysis, 2011
    Co-Authors: Valentin Mirceski, Dariusz Guziejewski, Witold Ciesielski
    Abstract:

    Cathodic stripping mechanism of an insoluble salt coupled with a homogenous chemical Reaction is considered both theoretically and experimentally under conditions of square-wave voltammetry. For the mercury Electrode in aqueous solution, the Electrode Reaction is described as L(aq) + Hg(l) = HgL(s) + 2e

  • electrochemical study of the pesticide methidathion at a mercury Electrode under cathodic stripping mode
    Croatica Chemica Acta, 2010
    Co-Authors: Valentin Mirceski, Dariusz Guziejewski, Slawomira Skrzypek, Witold Ciesielski
    Abstract:

    Methidathion, a non-systemic organophosphorous insecticide and acaricide is studied at the hanging mercury drop Electrode under cathodic stripping mode by means of cyclic and square-wave voltammetry (SWV). Its Electrode Reaction is analyzed in the light of recent theory of cathodic stripping processes of insoluble salts of SWV. Its complex Electrode mechanism is described by an Electrode Reaction of a second order, complicated by adsorption of methidathion molecules on the Electrode surface involving lateral interactions between each other. Moreover, under specific experimental conditions the Electrode mechanism can be additionally complicated by multilayer formation on the Electrode surface, as well as by a chemical transformation following the cathodic stripping process of the methidathion-mercury salt. Following the mechanistic study of the Electrode Reaction, a method for quantitative determination of methidathion is proposed applying SWV.

Junichiro Mizusaki - One of the best experts on this subject based on the ideXlab platform.

  • kinetics of the Electrode Reaction at the h sub 2 h sub 2 o porous pt stabilized zirconia interface
    Journal of The Electrochemical Society, 1994
    Co-Authors: Junichiro Mizusaki, Hiroaki Tagawa, Kensuke Isobe, Motoaki Tajika, Ikumasa Koshiro, Hideki Maruyama, Katsuhiko Hirano
    Abstract:

    Recently, much interest has been focused on the Electrode Reaction at the interface of porous Pt/stabilized zirconia in compound-gas mixtures such as CO-CO[sub 2], H[sub 2]-H[sub 2]O, CH[sub 4]-H[sub 2]O, and others, because this Reaction is important as a model of the Electrode Reaction in zirconia cells either for sensors, fuel cells, water electrolyzer, or other applications. To elucidate the mechanism of the Electrode Reaction at the interface of H[sub 2]-H[sub 2]O porous Pt/stabilized zirconia, measurements were made on the Electrode interface conductivity, [sigma][sub E], and the steady-state polarization current, I, as a function of H[sub 2] partial pressure, p[sub H2], and H[sub 2]O partial pressure, p[sub H2O], up to 800 C. The rate of the Electrode Reaction at 700 to 800 C in H[sub 2]-H[sub 2]O atmospheres is faster than that in CO-CO[sub 2] and slower than that in O[sub 2] rich atmospheres by 1 to 2 orders of magnitude. The rate-determining Reaction process was the exchange of adsorbed OH radicals between the Pt- and the stabilized zirconia-surface at the triple-phase boundary (TPB) of gas/Pt/stabilized zirconia.

  • kinetics of the Electrode Reaction at the h 2 h 2 o porous pt stabilized zirconia interface
    Journal of The Electrochemical Society, 1994
    Co-Authors: Junichiro Mizusaki, Hiroaki Tagawa, Kensuke Isobe, Motoaki Tajika, Ikumasa Koshiro, Hideki Maruyama, Katsuhiko Hirano
    Abstract:

    Recently, much interest has been focused on the Electrode Reaction at the interface of porous Pt/stabilized zirconia in compound-gas mixtures such as CO-CO[sub 2], H[sub 2]-H[sub 2]O, CH[sub 4]-H[sub 2]O, and others, because this Reaction is important as a model of the Electrode Reaction in zirconia cells either for sensors, fuel cells, water electrolyzer, or other applications. To elucidate the mechanism of the Electrode Reaction at the interface of H[sub 2]-H[sub 2]O porous Pt/stabilized zirconia, measurements were made on the Electrode interface conductivity, [sigma][sub E], and the steady-state polarization current, I, as a function of H[sub 2] partial pressure, p[sub H2], and H[sub 2]O partial pressure, p[sub H2O], up to 800 C. The rate of the Electrode Reaction at 700 to 800 C in H[sub 2]-H[sub 2]O atmospheres is faster than that in CO-CO[sub 2] and slower than that in O[sub 2] rich atmospheres by 1 to 2 orders of magnitude. The rate-determining Reaction process was the exchange of adsorbed OH radicals between the Pt- and the stabilized zirconia-surface at the triple-phase boundary (TPB) of gas/Pt/stabilized zirconia.