Electrochemical deprotonation of phosphate on stainless steel

Silva, Serge Da; Basseguy, Régine; Bergel, Alain

doi:10.1016/j.electacta.2004.04.039

Cited by 57 publications

(53 citation statements)

References 22 publications

(31 reference statements)

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“…The experimental data and the theoretical model proposed showed that a significant quantity of molecular hydrogen was produced by this mechanism, and the model suggested that the global reaction could be considered as reversible [29]. This reversibility may explain the influence of hydrogen removal on corrosion rate observed in the two-bottle experiments previously cited [12,26,27].…”

Section: Phosphates Srb and Hydrogenase In Anaerobic Biocorrosionmentioning

confidence: 73%

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Role of the reversible electrochemical deprotonation of phosphate species in anaerobic biocorrosion of steels

2007

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Sulphate reducing bacteria are known to play a major role in anaerobic microbiological influenced corrosion of steels, but mechanisms behind their influence are still source of debates as certain phenomena remain unexplained. Some experiments have shown that hydrogen consumption by SRB or hydrogenase increased the corrosion rate of mild steel. This was observed only in the presence of phosphate species. Here the cathodic behaviour of phosphate species on steel was studied to elucidate the role of phosphate in anaerobic corrosion of steel. Results showed: a linear correlation between reduction waves in linear voltammetry and phosphate concentration at a constant pH value; that phosphate ions induced considerable anaerobic corrosion of mild steel, which was sensitive to hydrogen concentration in the solution; and that the corrosion potential of stainless steel in presence of phosphate was shifted to more negative values as molecular hydrogen was added to the atmosphere in the reaction vessel. Phosphate species, and possibly other weak acids present in biofilms, are suggested to play an important role in the anaerobic corrosion of steels via a reversible mechanism of electrochemical deprotonation that may be accelerated by hydrogen removal.

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Section: Phosphates Srb and Hydrogenase In Anaerobic Biocorrosionmentioning

confidence: 73%

“…In a previous work [29] it was proved that the hydrogen atoms of the phosphate species were electrochemically reduced on stainless steel electrodes, according to the following reaction mechanism:…”

Section: Phosphates Srb and Hydrogenase In Anaerobic Biocorrosionmentioning

confidence: 99%

Role of the reversible electrochemical deprotonation of phosphate species in anaerobic biocorrosion of steels

2007

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“…1a indicates either successful buffering action of phosphate ions to release hydronium ions at close proximity of the surface or occurrence of direct reduction of weak acid, as previously proposed. [37][38][39][40] Taking various rate determining steps with different reactants, the hydrogen evolution reaction (HER) kinetics can be either zero-order or first-order in weak acid activities (the details of discussion are described in the supporting information). Due to the rapid buffering action and rapid kinetics of HER on Pt, we failed to experimentally differentiate the true reactant (hydronium ion vs. weak acid) on the Pt surfaces.…”

Section: Acs Paragon Plus Environmentmentioning

confidence: 99%

“…Alternatively, some claim that the weak acid itself 3 acts as the reactant under such conditions, although clear evidences of such "direct weak acid reduction " have not yet been documented. [37][38][39][40] The authors of such claims have shown that electric currents increase with the solute concentration up to 0.5 mol L −1 . Although higher concentrations were not investigated, 40 the performances under such conditions are speculated to be much higher.…”

Section: Introductionmentioning

confidence: 99%

Electrocatalytic Hydrogen Evolution under Densely Buffered Neutral pH Conditions

Takanabe

2015

J. Phys. Chem. C

104

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Under buffered neutral pH conditions, solute concentrations drastically influence the hydrogen evolution reaction (HER). The iR-free HER performance as a function of solute concentration was found to exhibit a volcano-shaped trend in sodium phosphate solution at pH 5, with the maximum occurring at 2 M. A detailed microkinetic model that includes calculated activity coefficients, solution resistance, and mass-transport parameters accurately describes the measured values, clarifying that the overall HER performance is predominantly governed by mass-transport of slow phosphate ions (weak acid). In the HER at the optimum concentration of approximately 2 M sodium phosphate at pH 5, our theoretical model predicts that the concentration overpotential accounts for more than half of the required overpotential. The substantial concentration overpotential would originate from the electrolyte property, suggesting that the proper electrolyte engineering will result in an improved apparent HER performances.

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“…For this scheme be effective, the presence of a final electron acceptor (e.g. an organic dye [13] or NAD + [24]) is required. On the contrary, there was no such final electron acceptor in the experiments reported here, and this scheme cannot be evoked.…”

mentioning

confidence: 99%

New hypotheses for hydrogenase implication in the corrosion of mild steel

Mehanna¹,

Basseguy²,

Délia³

et al. 2008

Electrochimica Acta

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The influence of [Fe]-hydrogenase from Clostridium acetobutylicum was studied on the anaerobic corrosion of mild steel. Two short-circuited mild steel electrodes were exposed to the same solution and hydrogenase was retained on the surface of only one electrode thanks to a dialysis membrane. The galvanic current and the electrode potential were measured as a function of time in order to monitor the difference in electrochemical behaviour induced by the presence of hydrogenase. A sharp potential decrease of around 500 mV was controlled by the deoxygenating phase. When hydrogenase was introduced after complete deoxygenation, significant heterogeneous corrosion was observed under the vivianite deposit on the electrode in contact with hydrogenase, while the other electrode only showed the vivianite deposit, * Alain.Bergel@ensiacet.fr, Phone : +33534615248, Fax : +33534615253 1 which was analysed by MEB and EDX. The effect of hydrogenase was then confirmed by monitoring the free potential of single coupons exposed or not to the enzyme in a classical cell after complete deoxygenating. In both phosphate and Tris-HCl buffers, the presence of hydrogenase increased the free potential around 60 mV and induced marked general corrosion. It was concluded that [Fe]-hydrogenase acts in the absence of any final electron acceptor by catalysing direct proton reduction on the mild steel surface.

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Electrochemical deprotonation of phosphate on stainless steel

Cited by 57 publications

References 22 publications

Role of the reversible electrochemical deprotonation of phosphate species in anaerobic biocorrosion of steels

Role of the reversible electrochemical deprotonation of phosphate species in anaerobic biocorrosion of steels

Electrocatalytic Hydrogen Evolution under Densely Buffered Neutral pH Conditions

New hypotheses for hydrogenase implication in the corrosion of mild steel

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