Inhibition of electrode processes on copper by AHT in acid solutions

✍ Scribed by J.W. Schultze; K. Wippermann

• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 736 KB
• Volume: 32
• Category: Article
• ISSN: 0013-4686
• DOI: 10.1016/0013-4686(87)85115-0

✦ Synopsis

Aktract-3-Atnino-5-heptyl-1,2,4-triazole (AHT)* is a very effective inhibitor of copper corrosion in neutral as well as acid solutions. From capacity-potential curves and their time dependence it follows that a compound layer of AHT (Cu, Cl) of 1-2 nm thickness is formed which is stable up to 0.4 V. At E > 0.45 V AHT is dissolved immediately. Current-potential curves were measured for all possible electrode reactions. The inhibitor affects the anodic oxidation of copper strongly. The cathodic oxygen reduction is influenced as well but to a lesser degree. The inhibition of the cathodic hydrogen evolution is only important in deaerated solutions and at large cathodic overvoltages. From the values and the shift of transfer coefficients we must conclude that the reaction site differs for transfer reactions of electrons, protons and copper ions. The influence of the AHT concentration is exnlained by the thickening of the layer, the conductivity of which differs for ions and electrons.