Designing Bimetallic Nanoparticle Catalysts via Tailored Surface Segregation

Bimetallic nanoparticles serve as a vital class of catalysts
with
tunable properties suitable for diverse catalytic reactions, yet a
comprehensive understanding of their structural evolution under operational
conditions as well as their optimal design principles remains elusive.
In this study, we unveil a prevalent surface segregation phenomenon
in approximately 100 platinum-group-element-based bimetallic nanoparticles
through molecular dynamics simulations and derive a thermodynamic
descriptor to predict this behavior. Building on the generality and
predictability of surface segregation, we propose leveraging this
phenomenon to intentionally enrich the nanoparticle surface with noble-metal
atoms, thereby significantly reducing their usage while maintaining
high catalytic activity and stability. To validate this strategy,
we investigate dozens of platinum-based bimetallic nanoparticles for
propane dehydrogenation catalysis using first-principles calculations.
Through a systematic examination of the catalytic sites on nanoparticle
surfaces, we eventually identify several candidates featuring a stable
Pt-enriched surface and superior catalytic activity, confirming the
feasibility of this approach.