Electrochemical behaviour of copper in aqueous moderate alkaline media, containing sodium carbonate and bicarbonate, and sodium perchlorate

The voltammetric polarization of Cu specimens in Na<sub>2</sub>CO<sub>3</sub>, NaHCO<sub>3</sub> and NaClO4 solutions (8-12pH range) has been investigated. Voltammetry data were complemented with SEM and electron microprobe analysis. Results are found to be in agr...

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Autores principales: Pérez Sánchez, M., Barrera, M., González, Sergio G., Souto, Ricardo M., Salvarezza, Roberto Carlos, Arvia, Alejandro Jorge
Formato: Articulo
Lenguaje:Inglés
Publicado: 1990
Materias:
Ciencias Exactas
Química
Electroquímica
Cobre
Carbonato de Sodio
voltammetry
Metales Alcalinos
scanning electron microscopy
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/81230
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-81230
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Ciencias Exactas
Química
Electroquímica
Cobre
Carbonato de Sodio
voltammetry
Metales Alcalinos
scanning electron microscopy
spellingShingle Ciencias Exactas
Química
Electroquímica
Cobre
Carbonato de Sodio
voltammetry
Metales Alcalinos
scanning electron microscopy
Pérez Sánchez, M.
Barrera, M.
González, Sergio G.
Souto, Ricardo M.
Salvarezza, Roberto Carlos
Arvia, Alejandro Jorge
Electrochemical behaviour of copper in aqueous moderate alkaline media, containing sodium carbonate and bicarbonate, and sodium perchlorate
topic_facet Ciencias Exactas
Química
Electroquímica
Cobre
Carbonato de Sodio
voltammetry
Metales Alcalinos
scanning electron microscopy
description The voltammetric polarization of Cu specimens in Na<sub>2</sub>CO<sub>3</sub>, NaHCO<sub>3</sub> and NaClO4 solutions (8-12pH range) has been investigated. Voltammetry data were complemented with SEM and electron microprobe analysis. Results are found to be in agreement with the passivation model developed for Cu in plain NaOH solutions. For the latter the process can be described in terms of two steps, namely, at low potentials the initial formation of a Cu<sub>2</sub>O thin layer followed by the growth of a massive Cu<sub>2</sub>O layer, and at higher potentials the appearance of a CuO-Cu(OH)<sub>2</sub> layer. These processes are accompanied by the formation of soluble Cu species. Beyond a certain potential which increases with the solution pH, copper pitting takes place. This model can be extended to Cu in carbonate/bicarbonate containing solutions by considering that Cu carbonates precipitate as long as soluble ionic Cu species are produced, without interfering appreciably with the formation of Cu oxides. The appearance of copper carbonate species is enhanced when pitting corrosion sets in. The precipitation of Cu carbonates occurs principally around pits. Cu pitting, although it is observed for all solutions, becomes more noticeable at the lowest pH values. At a constant pH, the density of pits increases in the order NaClO<sub>4</sub> > NaHCO<sub>3</sub> > Na<sub>2</sub>CO<sub>3</sub>. The influence of the electrolyte composition on Cu pitting is closely related to the blockage capability for pit nucleation and growth of the corresponding copper salts. Passivation in the Cu<sub>2</sub>O-Cu(OH)<sub>2</sub> region hinders pitting corrosion.
format Articulo
Articulo
author Pérez Sánchez, M.
Barrera, M.
González, Sergio G.
Souto, Ricardo M.
Salvarezza, Roberto Carlos
Arvia, Alejandro Jorge
author_facet Pérez Sánchez, M.
Barrera, M.
González, Sergio G.
Souto, Ricardo M.
Salvarezza, Roberto Carlos
Arvia, Alejandro Jorge
author_sort Pérez Sánchez, M.
title Electrochemical behaviour of copper in aqueous moderate alkaline media, containing sodium carbonate and bicarbonate, and sodium perchlorate
title_short Electrochemical behaviour of copper in aqueous moderate alkaline media, containing sodium carbonate and bicarbonate, and sodium perchlorate
title_full Electrochemical behaviour of copper in aqueous moderate alkaline media, containing sodium carbonate and bicarbonate, and sodium perchlorate
title_fullStr Electrochemical behaviour of copper in aqueous moderate alkaline media, containing sodium carbonate and bicarbonate, and sodium perchlorate
title_full_unstemmed Electrochemical behaviour of copper in aqueous moderate alkaline media, containing sodium carbonate and bicarbonate, and sodium perchlorate
title_sort electrochemical behaviour of copper in aqueous moderate alkaline media, containing sodium carbonate and bicarbonate, and sodium perchlorate
publishDate 1990
url http://sedici.unlp.edu.ar/handle/10915/81230
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