Experimental Evidence of Stability of Pt Clusters on and in Carbon Particles

Abstract

The stability of Pt clusters deposited on and embedded in carbon particles has been examined by in situ transmission electron microscopy. Commercial Pt clusters deposited on carbon particles began to move and coalesce upon heating above 150°C by surface melting coalescence, and the alterations were observed predominantly upon heating above 400°C. The embedded Pt clusters with the size of 1–3 nm disappeared by the diffusion of Pt atoms through the covered amorphous carbon layer upon heating above 1200°C. The Pt clusters embedded in carbon particles are more stable at higher temperatures about three times than the commercial Pt clusters deposited on carbon particles.