Copper corrosion in a simulated acid rain has been investigated by the electrochemical impedance analysis, the galvanostatic catholic-polarization, FT-IR and ICP-AES. Effects of pH and the Cl
- concentration on the rate and the mechanism of the corrosion were studied adding H
2SO
4 (or NaOH) and NaCl to the simulated acid rain respectively. The corrosion rate increased with decreasing pH, and with increasing Cl
- concentration. Warburg impedance resulting from a diffusion process for dissolved oxygen was observed at pH below about 3. The rate determining step of corrosion was found to be a film formation/dissolution process at pH≥3.5, and to be a diffusion process for dissolved oxygen at pH≤2.9. The film thickness increased with Cl
- addition to the simulated acid rain, but the film formed at the Cl
- concentration of 1000mg·dm
-3 was thinner than that of 100mg·dm
-3. This decrease in the film thickness at the Cl
- concentration of 1000mg·dm
-3 may result from the formation of CuCl whose solubility is much greater than that of Cu
2O which is one of the major components of the film at low Cl
- concentrations. The corrosion rate is thought to be controlled by CuCl
2- diffusion when the Cl
- concentration is high.
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