Effect of Surface Structure and Adsorption Phenomena on the Active Dissolution of Iron in Acid Media

Plonski, I. H.

doi:10.1007/978-1-4613-0327-5_3

Cited by 7 publications

(6 citation statements)

References 129 publications

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“…The anodic tafel slopes have been reported as 30 mV 55 and 40 mV 56 for iron in acid solutions The higher anodic tafel slopes are attributed to the measurements made in shorter immersion time. 3 The corrosion potential E corr values are found to be shifted in noble direction in the case of iodide ions where as, the values remain unaffected in the case of bromide and chloride ions. This shows that iodide ions affect the anodic reaction significantly whereas bromide and chloride ions affect both the reactions.…”

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confidence: 92%

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Corrosion inhibition of iron in 0.5 mol L-1 H2SO4 by halide ions

Jeyaprabha¹,

Sathiyanarayanan²,

Muralidharan³

et al. 2006

J. Braz. Chem. Soc.

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O efeito de inibição de íons haletos, tais como iodeto, brometo e cloreto, na corrosão de ferro em solução 0,5 mol L -1 de H 2 SO 4 , e o comportamento da adsorção desses íons na superfície do eletrodo, foram estudados pelos métodos de polarização e de impedância. Foi observada uma inibição de aproximadamente 90% para íons iodeto a 2,5 × 10 -3 mol L -1 e para íons brometo a 10 × 10 -3 mol L -1 , e de 80% para íons cloreto a 2,5 × 10 -3 mol L -1 . O efeito da inibição aumenta com o aumento da concentração dos íons haletos I -e Br -, mas decresce no caso do Cl -, para concentrações maiores que 5 ×10 -3 mol L -1 . Os valores de capacitância de dupla camada diminuíram consideravelmente na presença dos íons haletos, o que indicou que esses ânions são adsorvidos no ferro no potencial de corrosão.The inhibition effect of halide ions such as iodide, bromide and chloride ions on the corrosion of iron in 0.5 mol L -1 H 2 SO 4 and the adsorption behaviour of these ions on the electrode surface have been studied by polarization and impedance methods. It has been found that the inhibition of nearly 90% has been observed for iodide ions at 2.5 × 10 -3 mol L -1 , for bromide ions at 10 × 10 -3 mol L -1 and 80% for chloride ions at 2.5 × 10 -3 mol L -1 . The inhibition effect is increased with increase of halide ions concentration in the case of I -and Br -ions, whereas it has decreased in the case of Cl -ion at concentrations higher than 5 × 10 -3 mol L -1 . The double layer capacitance values have decreased considerably in the presence of halide ions which indicate that these anions are adsorbed on iron at the corrosion potential. Keywords: corrosion inhibition, iron, sulphuric acid, halide ions IntroductionAdsorption of anions over metal surfaces leading to the inhibitive or stimulation effects on metallic corrosion have been reported by earlier researchers. [1][2][3][4][5][6] It is well known that the dissolution of iron in H 2 SO 4 solutions occurs in four different states viz. active, passive, transpassive and brightening states as determined by the nature and kinetics of reaction involved, which depend on the potential and electrolyte composition. Combined adsorption of anions and cations together on the surface have also been studied. Electrostatic interaction is the main reason for the specific adsorption of anions on metal surface. 7,8 Possibility of chemisorption of the anions on metal by the formation of a covalent type bond is also suggested by Grahame. 9 Quantum chemical calculations have been used to describe the chemisorption of the halide ions on the metal electrode surface by the formation of partial charge transfer bonds. 10 Pearson suggested that the stability of the anion adsorption bond over metal surface should resemble to hard and soft acids and bases principle if the adsorption occurs by forming a donoracceptor type bond. 11,12 The specific adsorption behaviour of some of the anions on metal electrode surface and their effects on corrosion have been qualititatively related to this HSAB principle. 13,14 ...

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confidence: 92%

“…[1][2][3][4][5][6] It is well known that the dissolution of iron in H 2 SO 4 solutions occurs in four different states viz. active, passive, transpassive and brightening states as determined by the nature and kinetics of reaction involved, which depend on the potential and electrolyte composition.…”

Section: Introductionmentioning

confidence: 99%

Corrosion inhibition of iron in 0.5 mol L-1 H2SO4 by halide ions

Jeyaprabha¹,

Sathiyanarayanan²,

Muralidharan³

et al. 2006

J. Braz. Chem. Soc.

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“…The presence of these species as adsorbed intermediates during iron dissolution in acid media has been described previously. 17 , 37 …”

Section: Results and Discussionmentioning

confidence: 99%

“…The presence of these species as adsorbed intermediates during iron dissolution in acid media has been described previously. 17,37 Also, the oxidation of Fe ads 2+ to Fe ads 3+ is as described in model I reaction 17.…”

Section: Resultsmentioning

confidence: 99%

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Reaction Mechanisms of the Electrosynthesis of Magnetite Nanoparticles Studied by Electrochemical Impedance Spectroscopy

Reséndiz-Ramírez¹,

Rodríguez-López²,

Díaz-Real³

et al. 2021

ACS Omega

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This work presents a mechanistic study of the electrochemical synthesis of magnetite nanoparticles (NPs) based on the analysis of the electrochemical impedance spectroscopy (EIS) technique. After a discussion of the mechanisms reported in the literature, three models are devised and a prediction of their EIS spectra is presented. The approach consisted of the simulation of EIS spectra as a tool for assessing model validity, as EIS allows to characterize the relaxation of adsorbed intermediates. The comparison between the simulated impedance spectra and the experimental results shows that the mechanisms proposed to date do not explain all of the experimental results. Thus, a new model is proposed, in which up to three adsorbed intermediate species are involved. This model accounts for the number of loops found in experimental impedance data. The closest approximation of the features found in the experimental spectra by this proposed model suggests a better representation of the reaction mechanism within the evaluated potential range.

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Controlled‐Atmosphere Flame Fusion Single‐Crystal Growth of Non‐Noble fcc, hcp, and bcc Metals Using Copper, Cobalt, and Iron

et al. 2020

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The growth of noble‐metal single crystals via the flame fusion method was developed in the 1980s. Since then, there have been no major advancements to the technique until the recent development of the controlled‐atmosphere flame fusion (CAFF) method to grow non‐noble Ni single crystals. Herein, we demonstrate the generality of this method with the first preparation of fcc Cu as well as the first hcp and bcc single crystals of Co and Fe, respectively. The high quality of the single crystals was verified using scanning electron microscopy and Laue X‐ray backscattering. Based on Wulff constructions, the equilibrium shapes of the single‐crystal particles were studied, confirming the symmetry of the fcc, hcp, and bcc single‐crystal lattices. The low cost of the CAFF method makes all kinds of high‐quality non‐noble single crystals independent of their lattice accessible for use in electrocatalysis, electrochemistry, surface science, and materials science.

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Effect of Surface Structure and Adsorption Phenomena on the Active Dissolution of Iron in Acid Media

Cited by 7 publications

References 129 publications

Corrosion inhibition of iron in 0.5 mol L-1 H2SO4 by halide ions

Corrosion inhibition of iron in 0.5 mol L-1 H2SO4 by halide ions

Reaction Mechanisms of the Electrosynthesis of Magnetite Nanoparticles Studied by Electrochemical Impedance Spectroscopy

Controlled‐Atmosphere Flame Fusion Single‐Crystal Growth of Non‐Noble fcc, hcp, and bcc Metals Using Copper, Cobalt, and Iron

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