M. Drogowska et al., EFFECT OF TEMPERATURE ON COPPER DISSOLUTION IN NAHCO3 AND NAHCO3-SOLUTIONS AT PH-8(NACL AQUEOUS), Journal of the Electrochemical Society, 140(5), 1993, pp. 1247-1251
The effect of temperature between 5 and 60-degrees-C on the behavior o
f copper rotating-disk electrode was investigated in NaHCO3 and NaHCO3
+ NaCl solutions of 0.1-0.001 M at pH 8. Temperature rise had little
effect on the Cu(0) to Cu(I) oxidation (i.e., the first anodic peak in
voltammetric curves) and a strong eff ect at higher potentials of Cu(
II) oxidation state. The low activation energy, approximately 10 kJ mo
l-1, of Cu2O passive film formation is compatible with a poorly struct
ured layer. The Cu(II) passive film provided better protection for the
copper surface. The corrosion and breakdown potentials both show a li
near relationship with temperature. Corrosion potential decreased whil
e the breakdown potential increased with an increase of temperature. T
his may be a result of a dual eff ect of temperature: increase of Cu d
issolution rate and improved passivity characteristics of the precipit
ated Cu(II) products. The eff ect of temperature is considerably stron
ger for 0.1 and 0.05 M concentrations of NaHCO3 and NaHCO3 + NaCl solu
tions than in more dilute solutions.