Morphology of platinum clusters on graphite at different loadings

Molecular dynamics simulations of platinum atoms on a graphite surface have been performed with different coverages of platinum. The Sutton-Chen many body potential was used for the Pt-Pt interaction whereas a Steele potential with an energy minima representing adsorption sites was used to represent the carbon surface. The results show that platinum clusters can form on the graphite surface. The cluster size distribution shifts to larger clusters with increasing Pt loadings. The clusters at moderate loadings have a hcp close packed structure but, at very high loading, subdomains and a mixture of crystallinities are observed in a single cluster. The exposed surface area of the clusters at different loadings has also been calculated.