Influence of bicarbonate ions on the stability of prepassive layers formed on copper in carbonate-bicarbonate buffers

Journal Article · Fri Sep 01 04:00:00 EDT 1995 · Corrosion

DOI:https://doi.org/10.5006/1.3293631· OSTI ID:116516

Ribotta, S B; Folquer, M E ^[1]; Vilche, J R ^[2]

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1. Universidad Nacional de Tucuman (Argentina). Instituto de Quimica Fisica
2. Universidad Nacional de La Plate (Argentina). Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas

The dissolution and passivation of polycrystalline copper (Cu) electrodes in carbonate (CO{sub 3}{sup 2{minus}})-bicarbonate (HCO{sub 3}{sup {minus}}) solutions covering wide ranges of pH and electrolyte compositions were studied at 25 C. The influences of the CO{sub 3}{sup 2{minus}}-HCO{sub 3}{sup {minus}} concentration ratio and hydrodynamic conditions on electrodissolution of the base metal, on formation of prepassivating and passivating surface layers, and on chemical dissolution of the prepassive films were considered. Results obtained with a rotating disc electrode allowed the competing reactions related to the active-to-passive transition to be distinguished through the effects of potential scan rate and electrode rotation speed on the electrochemical behavior of the system at fixed concentrations of CO{sub 3}{sup 2{minus}} or HCO{sub 3}{sup {minus}}. Data were discussed on the basis of the interactions between HCO{sub 3}{sup {minus}} and Cu(II) oxide and hydroxide anodic products in the prepassive surface layer.

• Sponsoring Organization: USDOE
• OSTI ID: 116516
• Journal Information: Corrosion, Journal Name: Corrosion Journal Issue: 9 Vol. 51; ISSN 0010-9312; ISSN CORRAK
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CARBONATES
CONCENTRATION RATIO
COPPER
COPPER OXIDES
CORROSIVE EFFECTS
ELECTROCHEMICAL CORROSION
PASSIVATION
PH VALUE
PHASE TRANSFORMATIONS