Abstract

BEGUM, S. Nathira; BASHA, C. Ahmed  and  MURALIDHARAN, V.S.. Role of Halides on the Passivation of Iron in Alkaline Buffer Solutions. Port. Electrochim. Acta [online]. 2010, vol.28, n.3, pp.143-151. ISSN 0872-1904.

Cyclic voltammetric studies were carried out on pure iron in alkaline borate and phosphate buffer solutions at pH 10.8. At higher potentials, on anodic polarization, iron forms FeB4O7 and FeOOH in borate buffer, and FeHPO4 in phosphate buffer which got converted to higher valency phosphates. In phosphate solutions, in presence of halides, the interfacial diffusion layer turned to be cation selective outer sublayer and an anion selective inner sublayer, and in borate solutions a precipitate layer of metal oxyhydroxide was formed, which was anion selective, and anions adsorb on this.

Keywords : iron; cyclic voltammetry; passivity; alkaline corrosion; interfaces; anodic films.

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