Adsorption and diffusion of H and O on an Ni(1 1 1) surface containing different amounts of Cr

Das, Nishith Kumar; Shoji, Tetsuo

doi:10.1016/j.apsusc.2018.03.134

Cited by 26 publications

(8 citation statements)

References 75 publications

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“…As observed in catalysts containing more than one kind of transition metal, a large number of literature results have demonstrated that there is always an electronic effect between the metal components. ,− In other words, the electronic charge distributions of each metal in bimetallic or trimetallic catalysts differ from those when the metal is presented in the catalysts alone. To study the electronic effect in the PdNi(111)-A catalyst, we firstly investigated the charge distribution and the Mülliken charges.…”

Section: Resultsmentioning

confidence: 99%

Role of Ni in Bimetallic PdNi Catalysts for Ethanol Oxidation Reaction

Miao

Zhang

et al. 2018

J. Phys. Chem. C

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Bimetallic PdNi catalysts have garnered great interest in the study of ethanol oxidation reactions (EORs), though mechanistic insights into their catalytic performances are lacking, which hinders further improvement and rational design of the next generation of PdNi catalysts. As such, density functional theory (DFT) calculations were performed for six key elementary reactions using four model catalysts, one with pure Pd and three for PdNi. DFT results indicate that the reduced catalytic activities observed experimentally when Ni atoms were placed under Pd layers are the result of an increase in the reaction barrier for CH3COOH formation. Further analysis illustrated that this is largely owing to the charge transfer from the Ni to the Pd atoms. On the other hand, the enhanced activities of the PdNi catalysts with respect to pure Pd catalysts in EORs when Ni atoms are exposed at the catalyst surfaces are due to the lowering of the reaction barrier toward C–C bond cleavage and increasing of that toward C–O bond coupling. Therefore, surface Ni atoms are responsible for the superior activity of the PdNi catalysts in EORs. Further analysis of DFT results suggests that the reaction barriers of the C–C bond cleavage and the C–O bond coupling approach similar values when the composition of surface Ni atoms in a PdNi catalyst reaches about 44%. To achieve a complete EOR, the estimated surface Ni atoms should be as high as 77%. However, stability may become a concern for catalysts with such a high exposure of Ni atoms at the catalyst surface.

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Section: Resultsmentioning

confidence: 99%

Role of Ni in Bimetallic PdNi Catalysts for Ethanol Oxidation Reaction

Miao

Zhang

et al. 2018

J. Phys. Chem. C

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“…24 Not only are there different configurations for the atomic oxygen on the surface, but there are different coverage levels that should be explored, and configurations within those coverage levels. [92][93] Thus, the atoms may arrange differently at very dilute coverages, to when the coverage is increased to 0.25 ML (a quarter monolayer), 0.5 ML, and 1.0 ML. Beyond 1.0 ML, ultra-thin oxide layers will be formed, and then, beyond that, the bulk oxide will begin to be expressed.…”

Section: Oxidation Of Metallic Surfacesmentioning

confidence: 99%

“…Figure 9 shows the difference of O adsorption energy with different oxygen coverage to both Ni (111) and Ni-Cr(111) surfaces. 92 Depending on the stress imposed on the oxide by the underlying metal crystallography, the oxide film structure may or may not conform to the most thermodynamically stable bulk oxide phase. The possibilities are numerous and require careful evaluation, an evaluation that can be made within DFT.…”

Section: Oxidation Of Metallic Surfacesmentioning

confidence: 99%

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Density Functional Theory: An Essential Partner in the Integrated Computational Materials Engineering Approach to Corrosion

Taylor

2019

CORROSION

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The utility of density functional theory (DFT) for modeling in materials science and engineering with a focus on corrosion, is broadly introduced, along with an introduction to the technique, its inputs and outputs, and the risks and benefits. Case studies from the literature in which DFT is applied to problems such as the simulation of the properties of corrosion inhibitors, oxidation of metallic surfaces, localized corrosion, and the dissolution of metallic materials are then reviewed. Some speculations as to the future utility of DFT to further corrosion science and engineering are then made.

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“…Density functional theory (DFT), has been used to understand the effects of solute elements on repassivation of CRAs at the atomic level. 23 Adsorption of O and Cl to bare metal surfaces has been extensively studied for different pure metals, including Ni, [24][25][26][27][28] Fe, 29,30 Cr, 31 Al, 32,33 Mg, 34,35 and U, 36 focusing on the effect of different adsorption sites and adsorbate coverages. Alloys have also been investigated, including Samin et al who studied the adsorption of O on Ni-Cr binary alloys with doping element Mo.…”

mentioning

confidence: 99%

Application of the Chloride Susceptibility Index to Study the Effects of Ni, Cr, Mn and Mo on the Repassivation of Stainless Steels

Frankel

Taylor

2020

J. Electrochem. Soc.

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The effects of Ni, Cr, Mn and Mo on the very earliest stages of repassivation of stainless steels are quantified using the Chloride Susceptibility Index (CSI), which is an ab initio-based index for the evaluation of repassivation tendency. The quinary system of Fe-Ni-Cr-Mn-Mo is studied with density functional theory analysis and an electrochemisorption model developed previously by the authors, which are required to determine the CSI. The adsorption energies of O and Cl to different surface configurations are calculated, and then surface coverage maps of different species on the surface are obtained from the adsorption energies based on the Langmuir isotherm. Finally, CSI is calculated for different compositions of stainless steels. It is found that the effect of alloying elements on promoting repassivation of Fe alloys is in the order of Mn > ≈Ni > Cr > Mo when solute composition is less than 28 wt.%. A strong synergy is found between Cr and Mo such that a combination of these two elements at a certain ratio can give an optimal (low) CSI. The usage of CSI for evaluating repassivation tendency of CRAs is validated by experimental measured repassivation potential, which shows a strong monotonic negative relation with CSI.

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Adsorption and diffusion of H and O on an Ni(1 1 1) surface containing different amounts of Cr

Cited by 26 publications

References 75 publications

Role of Ni in Bimetallic PdNi Catalysts for Ethanol Oxidation Reaction

Role of Ni in Bimetallic PdNi Catalysts for Ethanol Oxidation Reaction

Density Functional Theory: An Essential Partner in the Integrated Computational Materials Engineering Approach to Corrosion

Application of the Chloride Susceptibility Index to Study the Effects of Ni, Cr, Mn and Mo on the Repassivation of Stainless Steels

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