2004 Volume 53 Issue 6 Pages 329-336
The electrochemical reactions of copper and carbon steel in LiBr solution have been investigated by electrochemical measurements including channel flow double electrode (CFDE) and electrochemical quartz crystal microbalance (EQCM). The active dissolution mechanism of copper in LiBr solution was proposed as follows.
The disproportional reaction of copper (Cu+Cu2+=Cu+) in LiBr solution was discussed by CFDE. The disproportional reaction rate was evaluated by detecting Cu (I) emitted from Cu working electrode in LiBr solution containing Cu (II) at an open circuit condition. It was found that the disproportional reaction was accelerated by the presence of LiBr, and the total reaction was proposed as follows.
The anodic polarization curve of carbon steel in LiBr solution shows the passivation at low anodic overvoltage region and the active dissolution by pitting corrosion at high anodic overvoltage region. Furthermore by using the quartz crystal which has 100kHz resonant frequency in EQCM, the anodic polarization curve and mass change of steel sheet electrode were measured simultaneosuly. Finally, the replacement reaction of carbon steel in LiBr solution containing Cu (II) was discussed by CFDE and EQCM.