Diffusion of Hydrides in Palladium Nanoclusters. A Ring-Polymer Molecular Dynamics Study of Quantum Finite Size Effects

• DOI: 10.1021/ct900554r
• Publication Date: 2010-01-13T12:54:35Z
• Authors: F. Calvo; D. Costa
• Keywords: Nanoclusters

The diffusion kinetics of hydrogen in bulk palladium and Pd nanoclusters containing up to 512 atoms has been theoretically investigated at 3% loading using ring-polymer molecular dynamics simulations. electronic ground-state energy surfaces are modeled an explicit many-body potential fitted reproduce the properties hydrides. constant, calculated by integration velocity autocorrelation function, shows Arrhenius behavior with inverse temperature. In addition, both prefactor activation found exhibit approximately linear variations cluster radius for sizes exceeding 128 atoms. Vibrational delocalization generally enhances diffusion, this effect being stronger clusters than bulk. An inherent structure analysis from positions centroids was used characterize mechanisms. Quantum effects lead not only a higher coordination (fcc) but also favor further softening outer layers.