Indirect interactions between the ionic liquid and Cu surface in 0.5 M HCl: a novel mechanism explaining cathodic corrosion inhibition

Abstract

Inhibition through blocking cathodic active points has been repeatedly reported for Cu corrosion mitigation in acids, yet basic molecular adsorptions cannot discriminate anodic form cathodic performance. This study first investigated copper corrosion in HCl without and with the ionic liquid using electrochemical and theoretical methods. The obtained results showed that more than 99% of the corrosion, according to EIS, decreased only by 2 mM of the inhibitor. Furthermore, a new mechanism was proposed considering the concept that the corroding Cu surface was unlikely to be free of reacting agents while the corrosion inhibition occurred. AIMD and XPS confirmed the mechanism.