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The Oxygen Evolution Reaction Drives Passivity Breakdown for Ni–Cr–Mo Alloys

Larsson, Alfred LU and Merte, Lindsay LU (2023) In Advanced Materials 35(39).
Abstract
Corrosion is the main factor limiting the lifetime of metallic materials, and a fundamental understanding of the governing mechanism and surface processes is difficult to achieve since the thin oxide films at the metal–liquid interface governing passivity are notoriously challenging to study. In this work, a combination of synchrotron-based techniques and electrochemical methods is used to investigate the passive film breakdown of a Ni–Cr–Mo alloy, which is used in many industrial applications. This alloy is found to be active toward oxygen evolution reaction (OER), and the OER onset coincides with the loss of passivity and severe metal dissolution. The OER mechanism involves the oxidation of Mo4+ sites in the oxide film to Mo6+ that can... (More)
Corrosion is the main factor limiting the lifetime of metallic materials, and a fundamental understanding of the governing mechanism and surface processes is difficult to achieve since the thin oxide films at the metal–liquid interface governing passivity are notoriously challenging to study. In this work, a combination of synchrotron-based techniques and electrochemical methods is used to investigate the passive film breakdown of a Ni–Cr–Mo alloy, which is used in many industrial applications. This alloy is found to be active toward oxygen evolution reaction (OER), and the OER onset coincides with the loss of passivity and severe metal dissolution. The OER mechanism involves the oxidation of Mo4+ sites in the oxide film to Mo6+ that can be dissolved, which results in passivity breakdown. This is fundamentally different from typical transpassive breakdown of Cr-containing alloys where Cr6+ is postulated to be dissolved at high anodic potentials, which is not observed here. At high current densities, OER also leads to acidification of the solution near the surface, further triggering metal dissolution. The OER plays an important role in the mechanism of passivity breakdown of Ni–Cr–Mo alloys due to their catalytic activity, and this effect needs to be considered when studying the corrosion of catalytically active alloys. (Less)
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author
and
contributor
LU and LU
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Advanced Materials
volume
35
issue
39
article number
2304621
publisher
John Wiley & Sons Inc.
external identifiers
  • scopus:85166340549
  • pmid:37437599
ISSN
1521-4095
DOI
10.1002/adma.202304621
language
English
LU publication?
yes
id
56437708-c2a4-49c9-aba8-28fa62f93808
date added to LUP
2023-10-23 15:05:50
date last changed
2024-01-23 03:00:08
@article{56437708-c2a4-49c9-aba8-28fa62f93808,
  abstract     = {{Corrosion is the main factor limiting the lifetime of metallic materials, and a fundamental understanding of the governing mechanism and surface processes is difficult to achieve since the thin oxide films at the metal–liquid interface governing passivity are notoriously challenging to study. In this work, a combination of synchrotron-based techniques and electrochemical methods is used to investigate the passive film breakdown of a Ni–Cr–Mo alloy, which is used in many industrial applications. This alloy is found to be active toward oxygen evolution reaction (OER), and the OER onset coincides with the loss of passivity and severe metal dissolution. The OER mechanism involves the oxidation of Mo4+ sites in the oxide film to Mo6+ that can be dissolved, which results in passivity breakdown. This is fundamentally different from typical transpassive breakdown of Cr-containing alloys where Cr6+ is postulated to be dissolved at high anodic potentials, which is not observed here. At high current densities, OER also leads to acidification of the solution near the surface, further triggering metal dissolution. The OER plays an important role in the mechanism of passivity breakdown of Ni–Cr–Mo alloys due to their catalytic activity, and this effect needs to be considered when studying the corrosion of catalytically active alloys.}},
  author       = {{Larsson, Alfred and Merte, Lindsay}},
  issn         = {{1521-4095}},
  language     = {{eng}},
  number       = {{39}},
  publisher    = {{John Wiley & Sons Inc.}},
  series       = {{Advanced Materials}},
  title        = {{The Oxygen Evolution Reaction Drives Passivity Breakdown for Ni–Cr–Mo Alloys}},
  url          = {{http://dx.doi.org/10.1002/adma.202304621}},
  doi          = {{10.1002/adma.202304621}},
  volume       = {{35}},
  year         = {{2023}},
}