Structure and adsorption properties of Cu–Au nanoparticles in harsh reactive environments
Year: 2025
Type: article
Abstract: The reactivity of nanoparticles is governed by their surface composition, which tends to vary significantly under reactive conditions. In this study, the impacts of temperature and the presence of a CO or O2 atmosphere on the structures of Au79, Cu19Au60, Cu39Au40, Cu60Au19, and Cu79 nanoparticles were investigated using a combination of global optimization, machine learning interatomic potentials, and density functional theory. We find that increasing gold content weakens CO and O adsorption and limits oxygen-induced structural changes, while copper-rich particles undergo pronounced oxidation and reconstruction. Bader charge analysis shows that, in bare nanoalloys, Au withdraws electron density from Cu due to their electronegativity difference. In oxidized Cu-Au nanoalloys, the charge on Cu atoms depends on the number of O neighbors and can reach values typical of Cu2O (0.6 e) and CuO (1.1 e). On average, the Cu atoms exhibit positive effective Bader charges of ∼0.9 e in these nanoalloys. Our results indicate that models of Cu-Au catalysts under oxidizing conditions must incorporate the full ensemble of metallic and oxidized configurations rather than a single most probable structure to predict true catalytic activity.
Source: The Journal of Chemical Physics
DOI: 10.1063/5.0288099
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
Awards: G1634667181, G2380881659
OpenAlex ID: W4414414442