Corrosion inhibition of copper in chloride solutions by pyrazole

The corrosion inhibition of copper in 0.1 M HCl in the presence of pyrazole was studied using potentiodynamic techniques with rotating disc and rotating ring disc electrode (RRDE). It was observed that the presence of pyrazole changes the mechanism of Cu dissolution in 0.1 M HCl. RRDE measurements showed that Cu+ was detected in the a;hole potential range studied, while Cu+2 was formed only at high anodic overpotentials. The addition of pyrazole decreases the rate of cuprous species formed and increases that of cupric species. Pyrazole behaves like a cathodic inhibitor and the inhibition efficiency is influenced by mass transport. (C) 2000 Elsevier Science Ltd. All rights reserved.