Abstract
Ring‐disk electrode measurements in the transpassive region indicated the dissolution of Cr mainly as Cr(VI) and partly as Cr(III). The conductivity of the anodic film strongly increased in the transpassive potential range, probably due to the formation of Cr(VI) species.
A kinetic model for the transpassive process was advanced to explain the observed experimental features. It comprises two dissolution paths of Cr as Cr(VI) and one as Cr(III). The formation of a Cr(IV) intermediate and a continuous change in the valence state of Cr at the film/solution interface are considered. Kinetic equations for both steady state and impedance response were derived and compared to experimental results to determine the reaction rate constants.
| Original language | English |
|---|---|
| Pages (from-to) | 2043-2050 |
| Journal | Journal of the Electrochemical Society |
| Volume | 145 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 1998 |
| MoE publication type | A1 Journal article-refereed |
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The mechanism of the transpassive dissolution of chromium in acidic sulfate solutions. / Bojinov, Martin; Fabricius, Gunilla; Laitinen, Timo; Saario, Timo.
In: Journal of the Electrochemical Society, Vol. 145, No. 6, 1998, p. 2043-2050.Research output: Contribution to journal › Article › Scientific › peer-review
TY - JOUR
T1 - The mechanism of the transpassive dissolution of chromium in acidic sulfate solutions
AU - Bojinov, Martin
AU - Fabricius, Gunilla
AU - Laitinen, Timo
AU - Saario, Timo
PY - 1998
Y1 - 1998
N2 - The transpassivity of chromium in 1 M sulfate solutions (pH 0 and 5) was studied by steady‐state polarization, rotating ring‐disk electrode voltammetry, and impedance spectroscopy in combination with the contact electric resistance technique. Ring‐disk electrode measurements in the transpassive region indicated the dissolution of Cr mainly as Cr(VI) and partly as Cr(III). The conductivity of the anodic film strongly increased in the transpassive potential range, probably due to the formation of Cr(VI) species. A kinetic model for the transpassive process was advanced to explain the observed experimental features. It comprises two dissolution paths of Cr as Cr(VI) and one as Cr(III). The formation of a Cr(IV) intermediate and a continuous change in the valence state of Cr at the film/solution interface are considered. Kinetic equations for both steady state and impedance response were derived and compared to experimental results to determine the reaction rate constants.
AB - The transpassivity of chromium in 1 M sulfate solutions (pH 0 and 5) was studied by steady‐state polarization, rotating ring‐disk electrode voltammetry, and impedance spectroscopy in combination with the contact electric resistance technique. Ring‐disk electrode measurements in the transpassive region indicated the dissolution of Cr mainly as Cr(VI) and partly as Cr(III). The conductivity of the anodic film strongly increased in the transpassive potential range, probably due to the formation of Cr(VI) species. A kinetic model for the transpassive process was advanced to explain the observed experimental features. It comprises two dissolution paths of Cr as Cr(VI) and one as Cr(III). The formation of a Cr(IV) intermediate and a continuous change in the valence state of Cr at the film/solution interface are considered. Kinetic equations for both steady state and impedance response were derived and compared to experimental results to determine the reaction rate constants.
U2 - 10.1149/1.1838595
DO - 10.1149/1.1838595
M3 - Article
VL - 145
SP - 2043
EP - 2050
JO - Journal of the Electrochemical Society
JF - Journal of the Electrochemical Society
SN - 0013-4651
IS - 6
ER -