Abstract
The kinetics of dissolved O
2 reduction and hydrogen evolution reactions on copper surface was studied in naturally aerated and air and O
2-saturated 0.50
mol/L H
2SO
4 solutions using polarization measurements combined with the rotating disc electrode (RDE). The Koutecky–Levich plot indicated that the dissolved O
2 reduction at the copper electrode was an apparent four-electron process. A correlation between the presence of dissolved O
2 and the formation of Cu
2O, confirmed from XRD, was discussed. Ascorbic acid (AA) was tested as a safe inhibitor for copper corrosion in H
2SO
4 solutions at 25
°C. Measurements were carried out as a function of dissolved oxygen concentration using Tafel polarization measurements. The addition of AA slowed down the reduction reaction of dissolved O
2 more effectively than the anodic reaction. Dissolved O
2 was found to enhance the inhibition performance of AA. Adsorption via hydrogen bonding was considered.