Determination of Parameters Useful for the Control of the Average Size of Pd Nanoparticles for C-Pd Composite

Carbon-palladium composites have been investigated by the method of transmission electron microscopy. The composites have been obtained by two different processes: physical vapor deposition (PVD) and chemical vapor deposition (CVD). The relation between the average size of a palladium particle, the time, and temperature has been carried out. The samples were annealed at different temperatures-from to but also for three different times, that is, 5 min, 10 min, and 30 min. Activation energies were calculated from the Arrhenius equation. Obtained values for PVD and PVD/CVD samples are: and , respectively. Determination of the activation energy will be useful in controlling the growth of palladium grains. Significant differences in values for both series resulted from encapsulation in graphite-palladium particles, which were obtained in the PVD/CVD process. Those graphite planes are formed at temperatures above and significantly slow down the growth of palladium particles.