Molecular Dynamics Simulations of Metal Clusters Supported on Fishbone Carbon Nanofibers

Abstract

The effect of the curvature of the carbon support material has been investigated by molecular dynamics simulations of a Pt_(100) and a Ni_(100) cluster adsorbed on fishbone-like carbon nanofibers using the ReaxFF reactive force field. Carbon nanocones both with and without hydrogen termination have been considered. Without hydrogen termination, significant differences are found between adsorbed Pt and Ni clusters for the dependence of the bond strain on the curvature. For instance, the support curvature does not seem to have an appreciable effect on the interatomic distances in adsorbed Pt clusters, while increased bond strain is observed for Ni clusters with increasing curvature. Since the bond length is related to a d-band shift as well as to a change in the bond order, it is concluded that the catalytic performance of Ni clusters can be enhanced by optimizing the curvature of the support material. In general, hydrogen termination attenuates the degree of metal-metal bond strain.

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