Titre :

Capturing the Iron Carburization Mechanisms from the Surface to Bulk

Auteur(s) :

Bentria, El Tayeb [Auteur]
Akande, Salawu Omotayo [Auteur]
Becquart, Charlotte [Auteur]
Unité Matériaux et Transformations (UMET) - UMR 8207
Mousseau, Normand [Auteur]
Bouhali, Othmane [Auteur]
El-Mellouhi, Fedwa [Auteur]

Titre de la revue :

The Journal of Physical Chemistry C

Nom court de la revue :

J. Phys. Chem. C

Numéro :

124

Pagination :

28569-28579

Éditeur :

American Chemical Society (ACS)

Date de publication :

2020-12-21

Mot(s)-clé(s) en anglais :

iron
dissociation
diffusion
molecules
Inorganic carbon compounds

Discipline(s) HAL :

Chimie/Matériaux
Physique [physics]/Matière Condensée [cond-mat]/Science des matériaux [cond-mat.mtrl-sci]

Résumé en anglais : [en]

Reactive force field molecular dynamics is a powerful tool to simulate large-scale reactive events such as catalytic reactions and metallic corrosion, including the carburization or so-called metal dusting corrosion. Building ...
Lire la suite >Reactive force field molecular dynamics is a powerful tool to simulate large-scale reactive events such as catalytic reactions and metallic corrosion, including the carburization or so-called metal dusting corrosion. Building on a vast set of reactive force field parameters, it aims to reduce the gap between computational and experimental observations. However, the production of different versions of reactive force field parameter sets in the past 2 decades demonstrates the challenges faced by developers when attempting to describe correctly and at the same time a broad range of environments, such as the kinetics of CO adsorption, dissociation, and carbon diffusion in iron systems. This has limited the ability of these force fields to capture the competing phenomena governing complex evolution such as the carburization of iron responsible for metal dusting corrosion. In this work, we demonstrate that it is possible to treat very different environments in an integrated way by expanding the ReaxFF parameter set, creating an environment-specific description. This approach enables us to capture both metallic surface-induced dissociation of carbon-containing gases such as carbon monoxide (CO) and atomic carbon bulk diffusion in iron systems within the same simulation setup so far unreachable with previously available force fields. Employing this extended-ReaxFF to describe a cell containing a gas mixture of carbon monoxide and argon reacting with an Fe(110) surface, we fully capture at the same time competing carburization reaction/diffusion processes on both the surface and the bulk. Analysis of the radial distribution function and charge density maps shows a variety of carbon bonds at different stages/layers, highlighting the diversity of the mechanisms captured while using our extended-ReaxFF. Interestingly, at a CO coverage higher than 0.7 monolayers, the atomic arrangement of the iron atoms is sufficiently altered to cause surface reconstruction leading to a significant increase in carbon diffusion. Moreover, we are able to observe and quantify the diffusion of Fe from the bulk toward the upper coke layer, computationally elucidating the slow but continuous coke formation reported experimentally, opening a wide range of opportunities to model various stages of iron carburization mechanisms.Lire moins >

Langue :

Anglais

Comité de lecture :

Oui

Audience :

Internationale

Vulgarisation :

Non

Établissement(s) :

Université de Lille
CNRS
INRA
ENSCL

Collections :

• Unité Matériaux et Transformations (UMET) - UMR 8207

Équipe(s) de recherche :

Métallurgie Physique et Génie des Matériaux

Date de dépôt :

2021-10-05T16:22:19Z
2021-10-06T12:44:36Z