Electrochemical behaviour of aluminium in concentrated NaOH solutions

Doche, Marie‐Laure; Rameau, J.J.; Durand, Robert; Novel-Cattin, Frédéric

doi:10.1016/s0010-938x(98)00107-3

Cited by 137 publications

(59 citation statements)

References 24 publications

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“…3. The anodic reaction is the dissolution of aluminium and the dominant cathodic reaction is the reduction of solvent water or methanol [21][22][23][24]. The corresponding electrode reactions are as follows:…”

Section: Surface Characterizationmentioning

confidence: 99%

“…In the anodic portion an almost constant potential-independent current density is achieved at relatively positive potentials. This behaviour can be explained in terms of the dissolution of aluminium through a porous product layer that permits charge transfer and ionic conduction [23][24]. In this range of potential aluminium may be considered to be in a pseudo-passivation state.…”

Section: Surface Characterizationmentioning

confidence: 99%

“…The surface layer consists of a loose and porous outer layer and a dense inside layer that may impede the mass transfer of reactive species and this may be responsible for the rapid potential increase in the later stage of aluminium anode discharge at higher current densities [21]. The EDAX results (Table 1) show that the molar ratio of aluminium and oxygen in the surface product is approximately 1:3, suggesting that the surface product on the discharged aluminium anode is mainly Al(OH) 3 [24]. The discharge of an aluminium anode at relatively higher current densities can result in an enrichment of aluminate ions Al(OH) 4 -in the electrolyte as well as a decrease in the alkalinity of the electrode interface.…”

Section: Surface Characterizationmentioning

confidence: 99%

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The corrosion and electrochemical behaviour of pure aluminium in alkaline methanol solutions

Wang

Shao

et al. 2007

J Appl Electrochem

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The corrosion and electrochemical behaviour of pure aluminium in alkaline methanol solutions has been investigated. The results of hydrogen collection experiments showed that aluminium has a lower corrosion rate in alkaline methanol solutions compared to water based solutions and that the corrosion rate increases with increasing water content of the solution. Polarization and galvanostatic discharge experiments showed that there is a wide potential window of electrochemical activity and a better discharge performance in the alkaline methanol solutions with a certain amount of water. Scanning electron microscopy (SEM) and energy dispersive analysis of X-ray (EDAX) showed that the passivation in the later stages of discharge in alkaline methanol solutions at relatively high current densities is due to the formation of a dense Al(OH) 3 layer on the surface of the anode.

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Section: Surface Characterizationmentioning

confidence: 99%

Section: Surface Characterizationmentioning

confidence: 99%

Section: Surface Characterizationmentioning

confidence: 99%

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The corrosion and electrochemical behaviour of pure aluminium in alkaline methanol solutions

Wang

Shao

et al. 2007

J Appl Electrochem

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“…[2][3][4][5][6][7][8][9] The potential dependence of anodic dissolution was revealed by measurement of the rate of concurrent cathodic hydrogen evolution. [4][5][6][7] The formation of aluminum hydroxide or oxide corrosion product films by dissolution has been deduced from studies of anodic kinetics using rotating disk electrodes, 2,6 and from ellipsometry. 3 Impedance studies have revealed complex dynamic behavior, which has been attributed to the contribution of multiple reaction steps to dissolution.…”

mentioning

confidence: 99%

Formation of Aluminum Hydride during Alkaline Dissolution of Aluminum

Adhikari

Lee

Hebert

2008

J. Electrochem. Soc.

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The role of hydrogen-containing surface species in the alkaline dissolution of aluminum was studied by secondary ion mass spectrometry ͑SIMS͒ and atomic force microscopy ͑AFM͒. The measurements revealed quasi-periodic nucleation and dissolution of large number densities of 10-100 nm size particles, during open-circuit dissolution in 1 M NaOH͑D͒ at room temperature. SIMS results using deuterated solutions, and prior Auger microprobe measurements, indicated that the particles were composed of aluminum hydride ͑deuteride͒, with an aluminum hydroxide ͑deuteroxide͒ surface layer. The measured open-circuit potential during dissolution was close to the Nernst potential of hydride oxidation. It was concluded that AlH 3 forms continuously during dissolution by reaction of cathodically generated hydrogen with the Al metal and is oxidized to aluminate ions ͓Al͑OH͒ 4 − ͔ in the accompanying anodic process. The present results are a direct confirmation of hydride formation on Al accompanying corrosion.

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“…In moderately basic solutions, the rate of anodic dissolution may be controlled by the combination of electrode kinetics, mass transport, or conduction through a surface film. [2][3][4][5][6][7] The dissolution reaction mechanism in concentrated KOH solutions was investigated by Macdonald et al using electrochemical impedance spectroscopy. 8 They determined that the metal corrodes by a reaction pathway in which OH − ions are added sequentially to Al atoms, until the stable aluminate ion, Al͑OH͒ 4 − , is formed.…”

mentioning

confidence: 99%

Participation of Aluminum Hydride in the Anodic Dissolution of Aluminum in Alkaline Solutions

Adhikari

Hebert

2008

J. Electrochem. Soc.

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The mechanism of anodic alkaline dissolution of aluminum was investigated through the analysis of cyclic voltammetry (CV) and potential step experiments. Attention was focused on the role of aluminum hydride (AlH3) as a reaction intermediate, as suggested by the recent detection of AlH3 formation during open-circuit dissolution. Potential step experiments at pH 11.75 revealed that the potential at the metal–surface film interface was close to the Nernst potential of AlH3 oxidation. This finding suggested a reaction mechanism in which an interfacial AlH3 layer is formed continuously by reaction of cathodically formed H with Al, and is then oxidized to the dissolution product, aluminate [Al(OH)4−] ions. However, potential step experiments at pH 11 did not indicate the presence of interfacial AlH3 ; instead, the metal–film interface was close to the equilibrium potential of Al oxidation. Analysis of the CV indicated an abrupt transition in dissolution behavior between the two pH values, from a relatively rapid dissolution controlled by diffusion and film conduction in highly alkaline solutions, to a slow dissolution at a lower pH controlled by a highly resistive surface film. The formation of interfacial AlH3 occurs readily at the higher pH, but is suppressed as the pH approaches neutrality.

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Electrochemical behaviour of aluminium in concentrated NaOH solutions

Cited by 137 publications

References 24 publications

The corrosion and electrochemical behaviour of pure aluminium in alkaline methanol solutions

The corrosion and electrochemical behaviour of pure aluminium in alkaline methanol solutions

Formation of Aluminum Hydride during Alkaline Dissolution of Aluminum

Participation of Aluminum Hydride in the Anodic Dissolution of Aluminum in Alkaline Solutions

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