Water splitting at an anion-exchange membrane as studied by impedance spectroscopy

Kniaginicheva, Ekaterina; Pismenskaya, Natalia; Melnikov, Stanislav; Belashova, Ekaterina; Sistat, Philippe; Cretin, Marc; Nikonenko, Victor

doi:10.1016/j.memsci.2015.07.050

Cited by 52 publications

(54 citation statements)

References 37 publications

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“…In the case of an anion-exchange membrane in NaCl solution, the transport number of the salt counterion, T Cl , is related to the transport numbers of the coions T Na and water splitting products T OH by the following equation: (6) Our previous studies [28][29][30] showed that at reduced potential drops (10-50 mV) that correspond to reaching the limiting state, the T OH values in the AMX and AMX-Sb membranes are negligible. The T Cl value found for these (unexposed to electric current) membranes in a 0.02 M solution is 0.999.…”

Section: Transport Numbers Of Counterionsmentioning

confidence: 99%

Evolution of Current–Voltage Characteristics and Surface Morphology of Homogeneous Anion-Exchange Membranes during the Electrodialysis Desalination of Alkali Metal Salt Solutions

Rybalkina

Tsygurina

Сарапулова

et al. 2019

Membr. Membr. Technol.

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It has been found that after 300 h of operation of AMX and AMX-Sb anion-exchange membranes (Astom, Japan) in overlimiting current regimes in the process of electrodialysis desalination of 0.02 M NaCl, NH 4 Cl, NaH 2 PO 4 , and KC 4 H 5 O 6 (KHT) solutions, the limiting currents, , determined by graphic processing of current-voltage curves increase in the order NaCl < NaH 2 PO 4 < KHT. Their increments relative to those for the "fresh" membrane are 33, 90, and 128%, respectively. The growth in is accompanied by an increase in the thickness of the samples occurring in the NaH 2 PO 4 and KHT solutions. In the case of NH 4 Cl, the values of decrease. It has been shown that a small decrease in counterion transport numbers during membrane operation has almost no effect on the values of limiting currents. The main contribution to the increase in is apparently made by electroconvection, which develops according to the mechanism of electroosmosis of the first kind. Its development is facilitated by the growth in the number and size of freestanding micrometer-sized cavities on the surface of anion-exchange membranes, the area and linear dimensions of which increase in the order NaCl < NaH 2 PO 4 < KHT. These cavities are formed as a result of enhancement of electrochemical degradation of the ion-exchange material and the inert filler polyvinyl chloride at the membrane/solution interface in ampholyte solutions.

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Section: Transport Numbers Of Counterionsmentioning

confidence: 99%

Evolution of Current–Voltage Characteristics and Surface Morphology of Homogeneous Anion-Exchange Membranes during the Electrodialysis Desalination of Alkali Metal Salt Solutions

Rybalkina

Tsygurina

Сарапулова

et al. 2019

Membr. Membr. Technol.

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“…The diffusion-limited current can only be exceeded (leading to OLC) if the preceding assumptions break down, by providing additional ions (via water splitting 11,51 or membrane discharge 22 ), activating new transport mechanisms (such as electro-osmotic instability, 9,11 surface conduction or electro-osmotic flow 12,13,16,31 ), or effectively shortening the diffusion length (by dendritic growth instability 33,34,49 ).…”

Section: Introductionmentioning

confidence: 99%

Impact of network heterogeneity on electrokinetic transport in porous media

Alizadeh

Bazant

Mani

2019

Journal of Colloid and Interface Science

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“…Charge carriers refers to the transfer of H + and OH -generated at the membrane-solution interface, as presented in Figure 15 (95). The rate of H + /OHgeneration depends on the intensity of the applied current and on the catalytic activity (i.e., the velocity of the reaction) between the membrane fixed charges and water (93).…”

Section: Water Splitting 21311 Charge Carriersmentioning

confidence: 99%

“…The hydroxyl groups generated are transferred through the membrane, causing an increase of the OH -concentration in the membrane phase. On the other hand, protons from water splitting reactions would be repulsed from the membrane phase (95). In practice, coion leakage may occur and protons may be transferred through an AEM under the Grotthuss mechanism (96).…”

Section: Water Splitting 21311 Charge Carriersmentioning

confidence: 99%

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Treatment of a cyanide-free copper electroplating solution by electrodialysis: study of ion transport and evaluation of water and inputs recovery

SCARAZZATO¹

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The two most common commercial copper baths are the acid sulfate copper bath and the alkaline cyanide copper bath. Alkaline copper baths are mostly used to coat parts with complex geometry and to avoid galvanic deposition when depositing a metal on a less noble substrate. Because of the toxicity of cyanide compounds, alternative baths have been developed using different complexing agents. The starting point of the present study is a cyanide-free strike bath developed for copper plating on Zamak substrates developed by the Institute for Technological Research of the State of São Paulo/ Brazil. The replacement of a raw material such as cyanide must be economically advantageous and technically feasible. Therefore, this study intended to propose an alternative to the treatment of liquid wastes from the mentioned bath, aiming at simultaneous water reclamation and chemicals recovery in a closed system. The electrodialysis membrane separation process was studied, using a laboratoryscale system operating with a synthetic solution simulating the rinsing waters from the HEDP-based bath. The feasibility of the technique was evaluated by analyzing operational parameters such as ion extraction, demineralization rate, concentration rate, current efficiency for each anionic specie and average energy consumption. Because HEDP is a chelating agent, the transport of Cu(II)-HEDP chelates through anion-exchange membranes was also evaluated by means of electrochemical methods. Chronopotentiometric and current-voltage curves were constructed for different model solutions containing the same compounds as the original bath. A relation between the presence of chelates in the solutions and the fixed ion exchange group could be established. Lastly, deposition tests were performed using electrolytes containing the recycled inputs and the characteristics of the coatings were analyzed. The results showed that an electrodialysis stack using strongly basic anion-exchange membranes was suitable to produce treated solutions and a concentrate containing the ions from the bath. The concentrate could be added to the copper bath to compensate eventual drag-out losses without affecting the quality of the coatings. Thus, the application of electrodialysis was shown to be a feasible alternative for recovering water and inputs from the evaluated solution, reducing the wastewater generation and saving natural resources.

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Water splitting at an anion-exchange membrane as studied by impedance spectroscopy

Cited by 52 publications

References 37 publications

Evolution of Current–Voltage Characteristics and Surface Morphology of Homogeneous Anion-Exchange Membranes during the Electrodialysis Desalination of Alkali Metal Salt Solutions

Evolution of Current–Voltage Characteristics and Surface Morphology of Homogeneous Anion-Exchange Membranes during the Electrodialysis Desalination of Alkali Metal Salt Solutions

Impact of network heterogeneity on electrokinetic transport in porous media

Treatment of a cyanide-free copper electroplating solution by electrodialysis: study of ion transport and evaluation of water and inputs recovery

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