(Digital Presentation) Understanding Kinetics of Metal Dissolution from Integrated Multiscale Simulations and Experiments

Abstract

Understanding dissolution kinetics is essential for predicting and mitigating materials corrosion; however, many mechanistic details still remain enigmatic. Examples include the evolution of solvation properties of ions and nature of electron transfer during dissolution. In this work, we integrate high-fidelity first-principles calculations based on grand-canonical density functional theory (DFT) and mesoscale simulations to predict dissolution kinetics of aluminum metal in acidic conditions. First, we show that the inclusion of an explicit solvation shell is crucial for accurately predicting the redox potential of metal dissolution. Second, we show that metal dissolution is governed by two kinetically limited processes, which are associated with the metal-metal bond breaking and ion diffusion within the electric double layer. Interestingly, it is found that kinetics and thermodynamics of these processes can be described with a simple model functionally based on Marcus theory, and their relative importance can be switched, depending on the applied potentials. Third, we show how dissolution kinetics derived from DFT is integrated with mesoscale simulations to elucidate the role of microstructure on the global metal dissolution. Comparison with experimental measurements will also be discussed. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and was supported with Laboratory Directed Research and Development funding under Project 20-SI-004.