Growth of Pt Clusters from Mixture Film of Pt–C and Dynamics of Pt Clusters

Abstract

A complete mixture film of carbon and platinum produced by coevaporation in a vacuum was directly heated in a transmission electron microscope. It was found that the diffusion and crystal growth of Pt clusters in the mixture film take place at approximately 500 °C. Pt clusters with a size of 2–5 nm were connected with each other in a parallel orientation or twin-crystal configuration in the mixture film. The growth of onion-like carbon with a hole at the center also occurred. The grown Pt clusters with twin-crystal structures appeared on and in the carbon film. The diffusion of Pt atoms in carbon was discussed as the problem of elusion in fuel cells. Direct observation of the movement of Pt clusters on and in the carbon film was carried out. The movement difference of Pt clusters in and on carbon film has been directly presented.