Thermodynamic Descriptors to Predict Oxide Formation in Aqueous Solutions

We formulate the maximum driving force (MDF) parameter as a descriptor to capture the thermodynamic stability of aqueous surface scale creation over a range of environmental conditions. We use free energies of formation, delta(f)G's, sourced from high-throughput density functional theory (DFT) calculations and experimental databases to compute the maximum driving force for a range of materials, including oxides and hydroxides of varying compositions. We show how to use the MDF to describe trends in the aqueous corrosion of nickel thin films determined from experimental linear sweep voltammetry data. We also show how to account for subsurface oxidation behavior using depth-dependent effective chemical potentials. We anticipate this approach will increase the overall understanding of oxide formation on chemically complex multielement alloys, where competing oxide phases can form during transient aqueous corrosion.

Automated summary

This study introduces the maximum driving force (MDF) parameter as a descriptor for capturing the thermodynamic stability of aqueous surface scale formation. By calculating the maximum driving force, it can describe the aqueous corrosion trend of nickel thin films and account for subsurface oxidation behavior. This approach is important for understanding oxide formation on complex alloys.