Stability and Electronic Properties of PtPd Nanoparticles via MD and DFT Calculations

The structural as well as electronic properties of PtPd nanoparticles (NPs) were investigated by using molecular dynamics simulations and density functional theory calculations. A wide range of NPs of different sizes (from 1.5 to 4 nm), structures (core–shell, alloy, Janus), and compositions were taken into consideration. It was shown that PtPd NPs of less than ∼2.0 nm are prone to structural transformations to icosahedral (Ih) shape, regardless of their initial structure and composition. On the other hand, for NPs of size ∼2.5 nm, the increase of temperature up to 700–900 K leads to structural changes only for compositions close to 40% Pt, which corresponds to energetic minimum for Pt@Pd NPs. The Ih form of Pd@Pt NPs with monolayer thickness of Pt on the surface appears to have the most negatively charged surface which makes this kind of NPs the best candidate for catalysis application.