Structural and dynamical evolution of bimetallic nanoalloys across length and time scales: Predicting oxidation effects on metal migration and dissolution at solid-liquid interfaces

Atomistic models provide effective approaches to study solid and liquid phases in isolation. Yet predicting the voltage-dependent stability and transient response of solid–liquid interfaces over relevant length and time scales remains an outstanding challenge. In response to this fundamental challenge, the goal of this project is to implement and further develop large-scale computational models based on voltage-dependent electronic-structure methods and charge-optimized many-body potentials for simulating electrochemical interfaces under applied bias. The focus is on predicting the electrochemical durability of platinum-based bimetallic electrodes against metal migration and metal dissolution under oxidizing conditions. Guided by the hypothesis that the adsorption of oxygenated species exerts primary control on the electrochemical stability of bimetallic alloys, we will predict and analyze the voltage-driven mechanisms by which these electrocatalysts degrade in aqueous media across length and time scales. This research is directly connected to three synergistic research themes of the BES Chemical Sciences, Geosciences, and Biosciences Division: 'Chemistry at Complex Interfaces', 'Chemistry in Aqueous Environments', and 'Charge Transport and Reactivity'. The anticipated broad benefit of this project is to advance computational capabilities for modeling solid–liquid interfaces under voltage and for predicting the charge capacity and redox activity of electrochemical systems, including but not limited to hydrogen fuel cells, metal–air batteries, and water-splitting electrolyzers.