Anodic hydrogen evolution on Mg

Abstract

We measured the anodic hydrogen evolution rates for various applied anodic current densities and estimated the corresponding cathodic hydrogen evolution rates. The estimated cathodic hydrogen evolution rates were less than the measured anodic hydrogen evolution rates, contradicting the enhanced catalytic activity mechanism of Mg corrosion. In addition, this model was contradicted by the measured apparent Mg valence of 1.2 ± 0.1. In contrast, the uni-positive Mg+ mechanism of Mg corrosion was supported by (i) the apparent Mg valence of 1.2 ± 0.1, and (ii) the fact that the measured anodic hydrogen evolution rate increased with increasing weight loss rate.