First Principles Modelling of Iron Oxide - Water Interfaces

The corrosion of metallic alloys is ubiquitous and managing the risk and cost of prevention, detection and mitigation is a serious issue in many industries. The electrochemistry of corrosion is well established and in some conditions it is possible to predict average corrosion rate and corrosion product formed. The molecular level details of the processes however remain obscure. The buried liquid-solid interface cannot be probed at the molecular level experimentally. We therefore do not know the transport mechanisms and reaction sites. We also do not know the fundamental reaction and charge transfer steps or their rates. As a result the current postulated reaction mechanisms, that underpin the rational design and choice of inhibition strategies for instance, are not validated beyond the reproduction of quantities like the average corrosion rate.

In this project first principles thermodynamics, based on hybrid exchange density functional theory, will be used to determine the phase stability, morphology, surface phases and reaction sites of iron oxide. The adsoption and reaction at these sites or aqueous species will be studied in order to document reaction mechanisms that occur during corrosion.