Abstract
The anodic dissolution of pure iron and binary iron-molybdenum alloys (10 and 20 wt% Mo) in molar H2SO4 and HCl solutions was studied by d.c. polarization and a.c. impedance techniques. Molybdenum additive influences both the steady state polarization curves and the impedance spectra in the two media, the impact being stronger for the Fe-20 wt % Mo alloy. In general, two-slope polarization curves are obtained for the alloys; impedance spectra exhibit two time constants in addition to the charge transfer one implying the existence of two reaction intermediates. Differences between spectra measured in H2SO4 and HCl are discussed. A kinetic model advanced on the basis of literature data for pure iron and molybdenum was able to reproduce quantitatively both the steady state and a.c. impedance results for both alloys in the two media. Kinetic parameters for the anodic dissolution of Fe-Mo alloys are thereby determined.
Similar content being viewed by others
References
C. Chao, L. Lin and D. D. Macdonald, J. Electrochem. Soc. 128 (1981) 1187.
Idem, ibid. 128 (1981) 1194.
Idem, ibid. 129 (1982) 1874.
D. D. Macdonald and M. Urquidi-Macdonald, ibid. 137 (1990) 2395.
D. D. Macdonald and S. I. Smedley, Electrochim. Acta 35 (1990) 1949.
D. D. Macdonald, J. Electrochem. Soc. 139 (1992) 3434.
M. Urquidi and D. D. Macdonald, ibid. 132 (1985) 555.
M. Urquidi-Macdonald and D. D. Macdonald, ibid. 136 (1989) 961.
M. Keddam, O. R. Mattos and H. Takenouti, ibid. 128 (1981) 257.
Idem, ibid. 128 (1981) 266.
D. R. MacFarlane and S. I. Smedley, ibid. 133 (1986) 2240.
O. E. Barcia and O. R. Mattos, Electrochim. Acta 35 (1990) 1003.
Idem, ibid. 35 (1990) 1601.
M. Bojinov, I. Betova and R. Raicheff, J. Electroanal. Chem. 381 (1995) 123.
Idem, Electrochim. Acta, in press.
M. Keddam, O. R. Mattos and H. Takenouti, Electrochim. Acta. 31 (1986) 1147.
Idem, ibid. 31 (1986) 1159.
J. A. L. Dobbelaar, E. C. M. Herman and J. H. W. de Wit, Corros. Sci. 33 (1992) 765.
Idem, ibid. 33 (1992) 779.
I. Annergren, M. Keddam, H. Takenouti and D. Thierry, Electrochim. Acta 38 (1993) 763.
K. Sugimoto and Y. Sawada, Corros. Sci. 17 (1977) 425.
K. Hashimoto, M. Naka, K. Asami and T. Masumoto, ibid. 19 (1979) 165.
D. Thierry, D. Persson, C. Leygraf, N. Boucherit and A. Hugot-le-Goff, Corros. Sci. 32 (1991) 273.
M. Keddam, H. Takenouti and N. Yu, J. Electrochem. Soc. 132 (1985) 2561.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Bojinov, M., Betova, I. & Raicheff, R. Influence of molybdenum on the anodic dissolution of iron in acidic solutions. J Appl Electrochem 26, 939–946 (1996). https://doi.org/10.1007/BF00242046
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00242046