A reactive force field molecular dynamics simulation of nickel oxidation in supercritical water

Ai, Liqiang; Zhou, Yisu; Huang, Haishen; Lv, Yongjun; Chen, Min

doi:10.1016/j.supflu.2017.10.025

Cited by 24 publications

(7 citation statements)

References 22 publications

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“…As shown in Figure 1, the Re-axFF provides a good fit of the state parameters of SCW, according to FEQ Helmholtz equation by Wagner and Pruss. [33] The FeCr austenitic stainless steel, which has been widely utilized as a structural material for the SCWR, is taken as the target material. Hence, the employed model is the face-centered cubic FeCr alloy, in which 12.5 at% atoms of the Fe substrate are randomly substituted by the Cr atoms.…”

Section: Methodsmentioning

confidence: 99%

Reactive molecular dynamics study of the oxidation behavior of iron‐based alloy in supercritical water

Jing

2021

Materials & Corrosion

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A theoretical study of the oxidation behavior of iron-based alloy in the supercritical water (SCW) has been carried out based on ReaxFF force-field molecular dynamics simulation. An atomic model has been proposed to simulate the initial chemisorption reactions and atoms diffusion behavior across the oxide layer. Simulation results imply that Cr addition has an important effect on the oxidation behavior of iron-based alloy. In the initial stage of oxidation, H 2 O prefers to adsorb on the Cr atom, and some species in the form of Cr(OH) 4 are observed on the FeCr alloy surface. Once an initial oxide layer is formed, further oxidation is controlled by the migration of vacancy. The O vacancies are formed at the oxide/FeCr alloy interface and migrate toward the steam, whereas Fe vacancies are formed at the oxide/steam interface and migrate toward the FeCr alloy. Attributed to the stronger binding energy of O-Cr bond than O-Fe bond, the Cr diffusivity in the oxide is less than Fe atoms. Thus, double oxide layers, including the inner Fe-Cr-O layer and outer Fe-O layer, are formed on the FeCr alloy, which is in good agreement with previous experimental observation.

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Section: Methodsmentioning

confidence: 99%

Reactive molecular dynamics study of the oxidation behavior of iron‐based alloy in supercritical water

Jing

2021

Materials & Corrosion

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“…By training the force field parameters out of the train sets calculated by quantum chemistry, ReaxFF is capable of reproducing the formation and dissociation of chemical bonds through its continuous profiles of bond order and interatomic distance . ReaxFF is computationally efficient, simulating a system with thousands of atoms for millions of timesteps in several days …”

Section: Introductionmentioning

confidence: 99%

“…There are several ReaxFF studies on metal oxidation with water or oxygen at the ambient environment or under the supercritical state. − In 2012, Aryanpour et al developed the first set of ReaxFF parameters for iron (Fe)–oxyhydroxide systems based on density functional theory calculations and the parameter set has been widely applied in subsequent ReaxFF studies. Pan et al , studied the process of iron oxidation under a typical moist condition and reported that a triplex structure was formed at the end of a three-stage oxidation process to reduce the overall oxidation speed.…”

Section: Introductionmentioning

confidence: 99%

“…Verners and van Duin simulated the Ni nanoplate stress corrosion in water, with the same ReaxFF parameter sets developed by Assowe et al Zou et al simulated the initial stage of oxidation of Ni in an oxygen atmosphere and proposed a new oxygen diffusion mechanism in which the oxygen atom diffuses via the movement of the oxygen-vacancy pair. Ai et al simulated the oxidation process of Ni in supercritical water and revealed that the dissociation of water is more likely to be a homolytic reaction instead of a heterolytic one under the supercritical state of relatively high temperatures and low densities. The above ReaxFF studies indicated that the ReaxFF method and the existing parameter sets are capable of describing metal reaction with H 2 O or O 2 .…”

Section: Introductionmentioning

confidence: 99%

“…11 ReaxFF is computationally efficient, simulating a system with thousands of atoms for millions of timesteps in several days. 14 There are several ReaxFF studies on metal oxidation with water or oxygen at the ambient environment or under the supercritical state. 12−21 In 2012, Aryanpour et al 13 developed the first set of ReaxFF parameters for iron (Fe)−oxyhydroxide systems based on density functional theory calculations and the parameter set has been widely applied in subsequent ReaxFF studies.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Role of Dissolved Oxygen in Iron Oxidation in Supercritical Water: Insights from Reactive Dynamics Simulations

Zhou

Chen

2019

J. Phys. Chem. C

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Oxygenated treatment is considered to be an effective chemical water treatment method and is widely used in supercritical power plants. Previous isotope tracer experiments reported that dissolved oxygen and supercritical water (scH2O) react with metals simultaneously, but the atomistic mechanism remains unrevealed. We performed reactive dynamics simulations to investigate the role of dissolved oxygen in iron oxidation in supercritical water. Structural analysis shows that the prior reacted O from O2 (O xy ) will activate the surface Fe atom to react with the O in scH2O (Owa), resulting in a Fe–O xy –Fe–Owa–H structure. Aside from activating Fe, O xy has another contribution of absorbing the proton generated after the dissociation of scH2O. These two roles of dissolved O2 result in an O2-boosted scH2O oxidation mechanism. A series of simulations indicate that appropriate O2 concentration will accelerate the formation of the surface protective oxide layer, whereas excessive O2 concentration might cause destructive internal oxidation of Fe. The increase of temperature has little influence on the formation of the surface oxide layer but will increase the internal oxidation rate of O2.

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Corrosion behaviors of iron in a supercritical CO2 environment: a molecular dynamics study

Guo,

Wang,

Tan

et al. 2023

J Mater Sci

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A reactive force field molecular dynamics simulation of nickel oxidation in supercritical water

Cited by 24 publications

References 22 publications

Reactive molecular dynamics study of the oxidation behavior of iron‐based alloy in supercritical water

Reactive molecular dynamics study of the oxidation behavior of iron‐based alloy in supercritical water

Role of Dissolved Oxygen in Iron Oxidation in Supercritical Water: Insights from Reactive Dynamics Simulations

Corrosion behaviors of iron in a supercritical CO2 environment: a molecular dynamics study

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