Hydrogen evolution during anodic polarization of Mg alloyed with Li, Ca, or Fe

A. Samaniego, N. Birbilis, X. Xia, G. S. Frankel

Research output: Contribution to journalArticleResearchpeer-review

Abstract

The origin of high rates of hydrogen evolution (HE) on dissolving Mg, the so-called negative difference effect, remains of practical interest. Recent studies have suggested that the ability of Mg to support the cathodic reaction is enhanced during dissolution and that enrichment of noble impurity elements at the dissolving Mg surface may also play a role in enhanced rates of HE. To begin to uniquely address the role played by other elements, Mg was intentionally alloyed with Li, Ca, or Fe. Hydrogen collection was performed during anodic galvanostatic polarization tests. An Mg-Li alloy containing 33 at% Li exhibited similar rates of anodic HE as pure Mg. Because Li dissolves with a valence of 1, any mechanism of anodic HE involving a lower valence state such as Mg, is therefore ruled out. Mg-Ca and Mg-Fe alloys exhibited higher rates of anodic HE than pure Mg. They also exhibited a minimum of the HE rate under cathodic polarization instead of at the open-circuit potential, the latter being the case for pure Mg and Mg-Li. The role of alloying elements in the HE on Mg and the implications for the mechanism of anodic HE are discussed.

Original languageEnglish
Pages (from-to)224-233
Number of pages10
JournalCorrosion
Volume71
Issue number2
DOIs
Publication statusPublished - 1 Feb 2015

Keywords

  • Alloying
  • Corrosion
  • Hydrogen evolution
  • Magnesium
  • Negative difference effect

Cite this

Samaniego, A., Birbilis, N., Xia, X., & Frankel, G. S. (2015). Hydrogen evolution during anodic polarization of Mg alloyed with Li, Ca, or Fe. Corrosion, 71(2), 224-233. https://doi.org/10.5006/1367
Samaniego, A. ; Birbilis, N. ; Xia, X. ; Frankel, G. S. / Hydrogen evolution during anodic polarization of Mg alloyed with Li, Ca, or Fe. In: Corrosion. 2015 ; Vol. 71, No. 2. pp. 224-233.
@article{5d8e4034d9cc4000a24370f42db54aee,
title = "Hydrogen evolution during anodic polarization of Mg alloyed with Li, Ca, or Fe",
abstract = "The origin of high rates of hydrogen evolution (HE) on dissolving Mg, the so-called negative difference effect, remains of practical interest. Recent studies have suggested that the ability of Mg to support the cathodic reaction is enhanced during dissolution and that enrichment of noble impurity elements at the dissolving Mg surface may also play a role in enhanced rates of HE. To begin to uniquely address the role played by other elements, Mg was intentionally alloyed with Li, Ca, or Fe. Hydrogen collection was performed during anodic galvanostatic polarization tests. An Mg-Li alloy containing 33 at{\%} Li exhibited similar rates of anodic HE as pure Mg. Because Li dissolves with a valence of 1, any mechanism of anodic HE involving a lower valence state such as Mg, is therefore ruled out. Mg-Ca and Mg-Fe alloys exhibited higher rates of anodic HE than pure Mg. They also exhibited a minimum of the HE rate under cathodic polarization instead of at the open-circuit potential, the latter being the case for pure Mg and Mg-Li. The role of alloying elements in the HE on Mg and the implications for the mechanism of anodic HE are discussed.",
keywords = "Alloying, Corrosion, Hydrogen evolution, Magnesium, Negative difference effect",
author = "A. Samaniego and N. Birbilis and X. Xia and Frankel, {G. S.}",
year = "2015",
month = "2",
day = "1",
doi = "10.5006/1367",
language = "English",
volume = "71",
pages = "224--233",
journal = "Corrosion",
issn = "0010-9312",
publisher = "NACE International",
number = "2",

}

Samaniego, A, Birbilis, N, Xia, X & Frankel, GS 2015, 'Hydrogen evolution during anodic polarization of Mg alloyed with Li, Ca, or Fe', Corrosion, vol. 71, no. 2, pp. 224-233. https://doi.org/10.5006/1367

Hydrogen evolution during anodic polarization of Mg alloyed with Li, Ca, or Fe. / Samaniego, A.; Birbilis, N.; Xia, X.; Frankel, G. S.

In: Corrosion, Vol. 71, No. 2, 01.02.2015, p. 224-233.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Hydrogen evolution during anodic polarization of Mg alloyed with Li, Ca, or Fe

AU - Samaniego, A.

AU - Birbilis, N.

AU - Xia, X.

AU - Frankel, G. S.

PY - 2015/2/1

Y1 - 2015/2/1

N2 - The origin of high rates of hydrogen evolution (HE) on dissolving Mg, the so-called negative difference effect, remains of practical interest. Recent studies have suggested that the ability of Mg to support the cathodic reaction is enhanced during dissolution and that enrichment of noble impurity elements at the dissolving Mg surface may also play a role in enhanced rates of HE. To begin to uniquely address the role played by other elements, Mg was intentionally alloyed with Li, Ca, or Fe. Hydrogen collection was performed during anodic galvanostatic polarization tests. An Mg-Li alloy containing 33 at% Li exhibited similar rates of anodic HE as pure Mg. Because Li dissolves with a valence of 1, any mechanism of anodic HE involving a lower valence state such as Mg, is therefore ruled out. Mg-Ca and Mg-Fe alloys exhibited higher rates of anodic HE than pure Mg. They also exhibited a minimum of the HE rate under cathodic polarization instead of at the open-circuit potential, the latter being the case for pure Mg and Mg-Li. The role of alloying elements in the HE on Mg and the implications for the mechanism of anodic HE are discussed.

AB - The origin of high rates of hydrogen evolution (HE) on dissolving Mg, the so-called negative difference effect, remains of practical interest. Recent studies have suggested that the ability of Mg to support the cathodic reaction is enhanced during dissolution and that enrichment of noble impurity elements at the dissolving Mg surface may also play a role in enhanced rates of HE. To begin to uniquely address the role played by other elements, Mg was intentionally alloyed with Li, Ca, or Fe. Hydrogen collection was performed during anodic galvanostatic polarization tests. An Mg-Li alloy containing 33 at% Li exhibited similar rates of anodic HE as pure Mg. Because Li dissolves with a valence of 1, any mechanism of anodic HE involving a lower valence state such as Mg, is therefore ruled out. Mg-Ca and Mg-Fe alloys exhibited higher rates of anodic HE than pure Mg. They also exhibited a minimum of the HE rate under cathodic polarization instead of at the open-circuit potential, the latter being the case for pure Mg and Mg-Li. The role of alloying elements in the HE on Mg and the implications for the mechanism of anodic HE are discussed.

KW - Alloying

KW - Corrosion

KW - Hydrogen evolution

KW - Magnesium

KW - Negative difference effect

UR - http://www.scopus.com/inward/record.url?scp=84988293874&partnerID=8YFLogxK

U2 - 10.5006/1367

DO - 10.5006/1367

M3 - Article

VL - 71

SP - 224

EP - 233

JO - Corrosion

JF - Corrosion

SN - 0010-9312

IS - 2

ER -