EVOLUTION OF THE RHODIUM COLLOID SUPPORTED ON GRAPHITE STUDIED BY ATOMIC-FORCE MICROSCOPY IN THE TAPPING MODE

Rhodium colloid stabilized by trioctylamine and deposited on a highly oriented pyrolitic graphite was studied by atomic force microscopy in the tapping mode. Most of the intact colloid particles are found to be agglomerated via two-dimensional islands or sphere-shaped clusters at tached to the steps of the graphite surface. No particle sintering occ urs after thermal treatments in vacuo at 100-550 degrees C. Oxidation at 550 degrees C leads to sintering of the particles contacting with t he carbon support but not within spherical 3D-aggregates. In addition, AFM images show the gasification trails following the Rh particles on graphite. Data indicate a strong colloid-support interaction under ox idative conditions.