Hydrogen on the Fe(110) surface and near bulk bcc Fe vacancies

Juan, Alfredo; Hoffmann, Roald

doi:10.1016/s0039-6028(98)00780-8

Cited by 80 publications

(41 citation statements)

References 54 publications

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“…The presence of a single H interstitial can therefore influence the bonding of at least 40 Fe atoms (octahedral H interstitial), and at least 38 Fe atoms (tetrahedral H interstitial), overall resulting in the weakening of the Fe bond strength. The weakening of Fe—Fe bonds due to the presence of interstitial H within the Fe lattice has been shown in several similar models in the literature [45, 60, 61, 62, 63, 64, 65, 66]. When H is present at an interstitial position within the Fe lattice an electron transfer of around 0.35 e − to 0.6 e − takes place from the Fe atom to the neighbouring H atom [45, 60, 66], which is well in the range of our estimation.…”

Section: Resultsmentioning

confidence: 68%

“…Another possibility is iron oxide could be reduced by hydrogen [44], thus destabilising any passive film, thus promoting localised corrosion and resulting in enhanced steel dissolution. It has also been proposed, that at the sub-surface level, the presence of H in the steel lattice could weaken the Fe—Fe bonds (suggested in one study to reduce bond strength ∼30%) [45], which correspondingly could lower the activation energy for Fe dissolution; possibly explaining H activated anodic dissolution.…”

Section: Introductionmentioning

confidence: 98%

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The effect of absorbed hydrogen on the dissolution of steel

Thomas

Ott

Schaller

et al. 2016

Heliyon

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Atomic hydrogen (H) was introduced into steel (AISI 1018 mild steel) by controlled cathodic pre-charging. The resultant steel sample, comprising about 1 ppmw diffusible H, and a reference uncharged sample, were studied using atomic emission spectroelectrochemistry (AESEC). AESEC involved potentiodynamic polarisation in a flowing non-passivating electrolyte (0.6 M NaCl, pH 1.95) with real time reconciliation of metal dissolution using on-line inductively coupled plasma-atomic emission spectroscopy (ICP-OES). The presence of absorbed H was shown to significantly increase anodic Fe dissolution, as evidenced by the enhanced detection of Fe2+ ions by ICP-OES. We discuss this important finding in the context of previously proposed mechanisms for H-effects on the corrosion of steels.

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Section: Resultsmentioning

confidence: 68%

Section: Introductionmentioning

confidence: 98%

The effect of absorbed hydrogen on the dissolution of steel

Thomas

Ott

Schaller

et al. 2016

Heliyon

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“…To study the atomic hydrogen adsorption on the Fe(110) surface an extended Hückel tight-binding (EHT) method has been applied recently [4]. The unit cell geometry was optimized using the atomsuperposition-and-electron-delocalization-molecular-orbital (ASED-MO) model core potential.…”

Section: Introductionmentioning

confidence: 99%

“…The system requires a top layer of cluster (or surface unit cell) that is at least equal in size to the NAC molecule. This means that the corresponding surface unit cell or cluster top layer should be even larger than that used in the EHT study of the H/Fe(110) system [4]. For the first-principle periodic approaches the requirements are even stricter since the unit cell should be further extended to exclude artificial adsorbate-adsorbate interaction arisen in such methods for small surface unit cells.…”

Section: Introductionmentioning

confidence: 99%

Reduction of Nitroaromatic Compounds on the Surface of Metallic Iron: Quantum Chemical Study

Zilberberg

Pelmenschikov

McGrath

et al. 2002

IJMS

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Abstract:The initial reduction steps of nitroaromatic compounds on the surface of metallic iron have been studied theoretically using nitrobenzene (NB) as a representative of nitroaromatic compounds. The quantum chemical cluster approximation within the semiempirical Neglect of Diatomic Differential Overlap for Metal Compounds method was applied to model the Fe(110) crystallographic surface, taken as a representative reactive surface for granular iron. This surface was modeled as a 39-atom two-layer metal cluster with rigid geometry. The associative and dissociative adsorption of nitrobenzene was considered. Based on our quantum chemical analysis, we suggest that the direct electron donation from the metal surface into the π * orbital of NB is a decisive factor responsible for subsequent transformation of the nitro group. Molecularly adsorbed NB interacts with metal iron exclusively through nitro moiety oxygens which occupy tri-coordinated positions on surface The charge transfer from metal to NB of approximately 2 atomic units destablizes the nitro group. As a result, the first dissociation of the N-O bond goes through a relatively low activation barrier. The adsorbed nitrosobenzene is predicted to be a stable surface species, though still quiet labile.

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“…28 The Fe and Pd first neighbors lose some electronic charge, as can be predicted by the higher electronegativity of H. Paul and Stautet report a charge of −0.30e − for H located at subsurface sites on a Pd(111) surface, while the Pd atoms lose some electronic charge. 29 The peak at −15.95 eV is made up mostly of H states, stabilized after absorption and positioned ≈ 8 eV below the E F , which is close to the state of a H at a Pd subsurface site.…”

Section: The Effect Of H On the Electronic Structurementioning

confidence: 92%

THE EFFECT OF H ON THE ELECTRONIC STRUCTURE OF AN Fe(110)–Pd(100) INTERFACE

et al. 2003

Self Cite

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The ion-driven mechanism in hydrogen permeation is substantially modified when iron is coated with palladium. A detailed knowledge of the electronic structure at the metal-metal interfaces is a prerequisite for understanding the process of H permeation. We have selected two low-Miller-index surfaces as a simple model for the interface. The system under consideration has 148 metallic atoms forming an Fe-Pd cluster distributed in six metallic layers.We have investigated the interaction of atomic hydrogen with the Fe(110)-Pd(100) interface using the semiempirical atom superposition and electron delocalization (ASED-MO) method. The changes in the electronic structures, density of states (DOS) and crystal overlap orbital population (COOP) in two different Fe-Pd interfaces were compared with the bulk ground states of both metals.The interfacial Fe-Pd distance results in about 1.74Å, whereas for the Fe-Pd first neighbors distance it is about 1.85Å. An important conclusion is that the metal-metal bonds at the interface are stronger than those bonds in the pure metal bulk. A favorable metal adhesion is observed, as revealed by the energetic stabilization of the composite metal system.H is stabilized near the FePd interface and stopped at the first Pd layer. A H-metal bond is developed with both Fe and Pd atoms while Fe-Pd bonding at the interface remains unaltered.

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Hydrogen on the Fe(110) surface and near bulk bcc Fe vacancies

Cited by 80 publications

References 54 publications

The effect of absorbed hydrogen on the dissolution of steel

The effect of absorbed hydrogen on the dissolution of steel

Reduction of Nitroaromatic Compounds on the Surface of Metallic Iron: Quantum Chemical Study

THE EFFECT OF H ON THE ELECTRONIC STRUCTURE OF AN Fe(110)–Pd(100) INTERFACE

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