Severe inhibition of the diffusion and electroactivity of Cu(bpy)2+2 complexes incorporated in Nafion® coatings on electrodes

Rong, Daiting; Anson, Fred C.

doi:10.1016/0022-0728(95)04339-x

Cited by 12 publications

(4 citation statements)

References 17 publications

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“…The oxygen reduction proceeds with the scheme: O 2 + 4H + + 4e → 2H 2 O, and depletion of either O 2 or H + would seriously affect the reaction kinetics, see eq 2. It is reported that the electroactivity of Cu(bpy) 2 2+ at the Nafion film coated platinum is severely inhibited by a drastic decrease in the diffusion rate of the complex , a slightly decreasing trend is observed for the O 2 concentration by impurity ion penetration, but it is not enough to account for the large decrease in j k,c (film).…”

Section: Discussionmentioning

confidence: 99%

Unprecedented Effect of Impurity Cations on the Oxygen Reduction Kinetics at Platinum Electrodes Covered with Perfluorinated Ionomer

et al. 1999

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Platinum electrodes covered with a perfluoro-sulfonated ionomer membrane show unique behaviors in comparison with bare platinum immersed in aqueous solutions. The electrochemical interface between the metal and the polymer can be different from the interface between the metal and the solution phase. In this context, platinum electrodes covered with such a polymer membrane are an interesting system, and deserve detailed study. Here the oxygen reduction reaction at the platinum surface covered with a perfluoro-sulfonated ionomer membrane is investigated kinetically in 0.1 N H2SO4 in the presence of 0.001 N Na+, K+, or Ca2+ ions, using rotating disk electrodes. It is discovered that the impurity ions, even in small amounts, hinder enormously the rate of the charge transfer step of oxygen reduction at the platinum covered with perfluoro-sulfonated ionomer. Especially the effect of Na+ in the membrane is very serious considering the fact that there exists only 2% Na+ of the exchange site in the membrane phase at this condition. Platinum covered with perfluoro-sulfonated ionomer membrane has historically attracted much research interest, based on the fact that oxygen concentration and H+ ion concentration in the membrane are both larger than those in normal acidic solutions, and could show larger catalytic activity than in bare platinum (Gottesfeld, S.; et al. J. Electrochem. Soc. 1987, 134, 1455. Lawson, D. R.; et al. J. Electrochem. Soc. 1988, 135, 2247). However, this expectation encountered disappointing failure (Zecevic, S. K.; et al. J. Electrochem. Soc. 1997, 144, 2973). Results here indicate that such a paradox could be accounted for by the effect of the metal−polymer interface that alters the reaction conditions of oxygen reduction.

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Section: Discussionmentioning

confidence: 99%

Unprecedented Effect of Impurity Cations on the Oxygen Reduction Kinetics at Platinum Electrodes Covered with Perfluorinated Ionomer

et al. 1999

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“…For Os(bpy) 3 3/2 -and Co(bpy) 3 2/1 -Nafion systems [25,27], increases in D with C f have actually proved a significant electron hopping between redox sites. Contrary to the change expected from electron-hopping transport, several groups have reported decreases in D with increased loading [2,28,29]. These decreases have been ascribed to the effect of electrostatic cross-linking between incorporated redox ions and oppositely charged polymer lattices, or to the ion-transfer rate limited by a decreasing residence site [25,30].…”

Section: Potential-step Chronoamperometrymentioning

confidence: 78%

Electrochemical Study of the Binding Interaction Between Dihydroxybenzenesulfonates and Viologen-Linked Polypyrrole

et al. 2002

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“…The transport is influenced by the saturation of the membrane with a cation and its hydrophilicity. High saturation, especially with big hydrophobic complex cations, impedes the physical diffusion of the complex due to the dehydration of the membrane [25,26]. In such a case, however, there is still the possibility of an electron hopping from one reduced molecule to an adjacent oxidized one [27].…”

Section: Phenanthroline Derivativesmentioning

confidence: 99%

Modification of Glassy Carbon Electrodes with Complexes of Manganese(II) with Some Phenanthroline Derivatives Immobilized in Nafion Layer

Tomczyk,

Seliger

2024

IJMS

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Manganese(II) complexes with phenanthroline derivatives modified with different substituents were synthesized and incorporated into Nafion layers covering the surfaces of glassy carbon electrodes and were studied electrochemically. Formal potentials and apparent diffusion coefficients were calculated and discussed. The suitability for electrocatalytic oxidation of ascorbic acid and glycolic acid was examined. The surfaces of modified electrodes were characterized using atomic force microscopy.

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Severe inhibition of the diffusion and electroactivity of Cu(bpy)2+2 complexes incorporated in Nafion® coatings on electrodes

Cited by 12 publications

References 17 publications

Unprecedented Effect of Impurity Cations on the Oxygen Reduction Kinetics at Platinum Electrodes Covered with Perfluorinated Ionomer

Unprecedented Effect of Impurity Cations on the Oxygen Reduction Kinetics at Platinum Electrodes Covered with Perfluorinated Ionomer

Electrochemical Study of the Binding Interaction Between Dihydroxybenzenesulfonates and Viologen-Linked Polypyrrole

Modification of Glassy Carbon Electrodes with Complexes of Manganese(II) with Some Phenanthroline Derivatives Immobilized in Nafion Layer

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