Discovering the Fundamental Processes of Anodic Mg Corrosion Through Ab Initio Calculations

The longevity of materials is an essential component of a sustainable economy. It is closely linked to our ability to control corrosion through materials design, which requires a fundamental understanding of the mechanism that leads to corrosion, starting with the most basic process of metal dissolution. Investigations based on electronic density functional theory seem predestined to provide insights at the most fundamental level of electrons, atoms and molecules.<br/>Over the last few years, we have developed an efficient computational electrode [Phys. Rev. Lett. <b>120</b>, 246801 (2018)] and a thermopotentiostat [Phys. Rev. Lett. <b>126</b>, 136803 (2021)] approach that enable realistic calculations of electrified solid/liquid interfaces under potential control. The unprecedented insight into atomic-scale processes provided by these developments will be demonstrated using the example of the anodic corrosion of Mg. The processes underlying the observed enhanced hydrogen evolution and Mg dissolution have remained elusive for more than 150 years, despite intensive investigation. Our study reveals two previously unknown mechanisms that provide a completely new perspective on experimental results that have eluded interpretation [Deißenbeck at al (submitted)].