Localization of the Work Function on Compositionally Complex Surfaces

Determine whether the work function remains a property of the bare surface as a whole on compositionally complex Ag-Au-Pd-Pt alloy surfaces, or whether it becomes localized to specific surface sites such that a site-resolved work function provides additional information about hydrogen-evolution activity.

Background

The paper evaluates the bare-surface work function as an HER activity descriptor for Ag-Au-Pd-Pt alloys and treats it as a single property averaged over each modeled surface. Although this quantity predicts activity well, its predictive information largely overlaps with that contained in coverage-corrected hydrogen adsorption energies and composition.

The authors therefore leave unresolved whether the whole-surface treatment is physically appropriate for compositionally complex surfaces. Local variations in electronic structure could make a site-resolved work function more informative, particularly because these alloys expose distributions of chemically distinct adsorption environments. Resolving this issue would clarify whether work-function effects provide an independent, spatially localized descriptor under realistic alloy conditions.