Morphological Stability of Au‐Core Nanosatellites

Hybrid metallic nanoalloys combining plasmonic and catalytic metals are essential for the development of advanced photocatalysts. Gold core–satellites—nanostructures featuring a gold core decorated with smaller transition metal clusters—are shown to offer high photocatalytic activity. Notwithstanding, their morphological formation and stability remain poorly explored. Using classical molecular dynamics simulations at relatively high temperatures, we study the morphological evolution of an Au core with Rh, Pt, or Pd satellites. A time scale of ns is long enough to detect the main morphological changes. We introduce a clustering approach and a Spearman analysis to identify correlations among geometrical descriptors. Chemical reordering of AuRh, AuPt, and AuPd core–satellites is not correlated with structural changes, and nanoalloys never undergo any solid–liquid transitions. Among them, AuRh core–satellite morphology exhibits the highest stability, with the two metals maintaining distinct domains. In contrast, only 25 of AuPt nanoalloys preserve a core–satellite morphology, and less than 15% in the case of AuPd. AuPt and AuPd rearrange into single, often icosahedral aggregates within ns. AuPt forms an Au shell with a non‐negligible interdiffusion of Pt within the subsurface for Pt seeds smaller than 561 atoms. AuPd shows a significant Pd interdiffusion and mixing.