The anodic and cathodic dissolution of α-phase Zn-68Al in alkaline media

Abstract

The mechanisms of Zn and Al dissolution of a pure α-phase Al-Zn in an alkaline electrolyte have been characterized using atomic emission spectroelectrochemistry to decouple the elementary dissolution rates. It was found that the selective dissolution of Al leads to the formation of a metallic Zn(0) surface layer. In the metallic form, this layer did not seem to affect the dissolution rate of Al. However, its oxidation led to a significant decrease in the Al dissolution rate, referred to as the negative correlation effect. These mechanisms were identified and characterized via linear sweep voltammetry and potentiostatic experiments.