Adsorbate-catalyzed corrosion

McBride, John R.; Soriaga, Manuel P.

doi:10.1016/0022-0728(91)85131-8

Cited by 18 publications

(8 citation statements)

References 14 publications

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“…This efficient screening is, of course, absent in the bulk ionic solid, and this leads to pronounced shifts in Fe and S core-level spectra relative to those observed for bulk FeS and FeS 2 . 20 Similar effects have been observed for I/Pd 24 and there is suggestive evidence for other metal-halide systems. 25 -27 The XPS studies of monolayer coverages of iodine on Pd emersed from aqueous solution indicate that iodine is in a zerovalent state.…”

Section: Introductionsupporting

confidence: 79%

“…25 -27 The XPS studies of monolayer coverages of iodine on Pd emersed from aqueous solution indicate that iodine is in a zerovalent state. 24 In situ scanning tunneling microscopy (STM) studies 25 of halide adsorption on Cu(111) indicate that adsorbed species have radii appropriate to zero-valent oxidation states. Chlorine adsorbed on Ag surfaces acts as a siteblocker to H 2 O dissociation under ultrahigh vacuum (UHV) conditions, 26 which suggests a similar zero-valent state.…”

Section: Introductionmentioning

confidence: 99%

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Adsorbate‐catalyzed anodic dissolution and oxidation at surfaces in aqueous solutions

Kelber

Seshadri

2001

Surface & Interface Analysis

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Certain adsorbates, particularly sulfur and iodine, present at submonolayer coverages catalyze anodic dissolution or oxidation at selected transition metal surfaces. No change in adsorbate surface coverage or oxidation state is observed during the dissolution process, indicating that the process is truly catalyzed by the adsorbed impurity. This allows enhanced dissolution to take place in environments entirely free of solvated forms of the impurity. In the case of iodine, the mechanism depends in part on the relative strength of iodine-metal vs. metal-metal bond strengths, but also depends on other factors that are as yet poorly understood. In the case of adsorbed sulfur, the effect is related to the ability of adsorbed sulfur to hinder the formation of an oxide layer via the complete dissociation of water at the solid surface. The relevance of these adsorbate-catalyzed processes to intergranular stress corrosion cracking and semiconductor device processing are discussed.

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Section: Introductionsupporting

confidence: 79%

Section: Introductionmentioning

confidence: 99%

Adsorbate‐catalyzed anodic dissolution and oxidation at surfaces in aqueous solutions

Kelber

Seshadri

2001

Surface & Interface Analysis

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“…In this paper, we present results based upon EC−STM that extend the detail of information known about adsorbate-catalyzed anodic dissolution, a relatively under-studied interfacial phenomenon, in which the corrosion of a metal substrate is induced by a single monolayer of certain adsorbates in a solution devoid of corrosion promoters. − …”

Section: Introductionmentioning

confidence: 83%

Adsorbed-Iodine-Catalyzed Dissolution of Pd Single-Crystal Electrodes: Studies by Electrochemical Scanning Tunneling Microscopy

Sashikata¹,

Matsui²,

Itaya³

et al. 1996

J. Phys. Chem.

102

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Unfettered anodic dissolution occurs in halide-free sulfuric acid solutions for Pd electrodes pretreated with a single chemisorbed layer of iodine atoms; no dissolution takes place in the absence of iodine. Tandem cyclic voltammetry and in situ scanning tunneling microscopy have been employed to investigate the mechanism of this type of corrosion under low-current conditions. The ordered adlattices studied were those spontaneously formed upon immersion of the Pd single-crystal surface to a dilute solution of iodide: Pd(111)-( 3 × 3)-R30°-I; Pd(100)-c(2 × 2)-I; Pd(110)-pseudohexagonal-I. It has been found that (i) adsorbed-iodine-catalyzed corrosion of Pd is a structure-sensitive reaction; it decreases in the order Pd(110)-I > Pd(111)-I g Pd(100)-I. (ii) At Pd(111)-I, dissolution occurs exclusively at step-edges in a layer-by-layer sequence without deterioration of the iodine adlattice structure. (iii) At Pd(100)-I, dissolution takes place anisotropically along a step aligned in the {100} direction but in a layer-by-layer process without disruption of the iodine adlattice structure. (iv) At Pd(110)-I, dissolution transpires predominantly at a step-edge that runs parallel to the {100} direction; pit formation at terraces precluded layer-by-layer dissolution and led to progressive disorder of the substrate structure. Heuristic models are presented to account for these observations.

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“…The siteselective anodic dissolution of Pd in noncorrosive electrolyte catalyzed by a monolayer of iodine was first reported based upon low-energy electron diffraction (LEED). [6][7][8] The dissolution of Pd(111) and Pd(100) surfaces was found to follow a layer-by-layer mechanism. This phenomenon of adsorbatecatalyzed corrosion was recently investigated further by in situ STM.…”

Section: Introductionmentioning

confidence: 97%

“…The characterization of anodic dissolution and cathodic deposition processes at metal electrodes is of fundamental and practical interest in electrochemical surface science. The site-selective anodic dissolution of Pd in noncorrosive electrolyte catalyzed by a monolayer of iodine was first reported based upon low-energy electron diffraction (LEED). − The dissolution of Pd(111) and Pd(100) surfaces was found to follow a layer-by-layer mechanism. This phenomenon of adsorbate-catalyzed corrosion was recently investigated further by in situ STM.…”

Section: Introductionmentioning

confidence: 99%

Effect of Adsorbed Iodine on the Dissolution and Deposition Reactions of Ag(100): Studies by In Situ STM

Teshima¹,

Ogaki²,

Itaya³

1997

J. Phys. Chem. B

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In situ scanning tunneling microscopy has been employed to determine the structure of iodine adlayers formed on Ag(100) and to evaluate the role of such adlayers in the dissolution and deposition reactions of the substrate in perchloric acid. In the double-layer potential region, iodine was found to possess a c(2 × 2) structure; this structure was unaffected by anodic dissolution of the Ag substrate. On both bare and I-pretreated Ag(100) surfaces, the anodic dissolution of Ag occurred exclusively at step-edges in a layer-by-layer mechanism. However, whereas jagged monatomic step lines were found on the I-free surface, relatively smooth (straight) step lines existed along the direction of iodine atomic rows ({100}) on the Ag(100)-I surface. Etching rates on Ag(100)-I were dependent on the direction of the step-edges, which suggests that the adlayer near such edges plays a crucial role in the dissolution reaction. The deposition of Ag on Ag(100)-I was also found to occur preferentially at step-edges aligned along a particular direction. A model is proposed to explain the anisotropic dissolution and deposition.

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Adsorbate-catalyzed corrosion

Cited by 18 publications

References 14 publications

Adsorbate‐catalyzed anodic dissolution and oxidation at surfaces in aqueous solutions

Adsorbate‐catalyzed anodic dissolution and oxidation at surfaces in aqueous solutions

Adsorbed-Iodine-Catalyzed Dissolution of Pd Single-Crystal Electrodes: Studies by Electrochemical Scanning Tunneling Microscopy

Effect of Adsorbed Iodine on the Dissolution and Deposition Reactions of Ag(100): Studies by In Situ STM

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