Background: Deposition of the palladium nanoparticles from colloidal solution on various supports produces palladium catalysts with a predetermined size and concentration of the palladium nanoparticles, which allows to study the nanosize effects and support influence on palladium catalytic properties.
Objective: The goal of the present work was a development of the preparation method of systems with the supported on γ-Al 2 O 3 palladium nanoparticles with a controlled size and determination of their thermal stability in the oxidizing and reducing atmospheres.
Method: We have demonstrated the preparation of Pd/γ-Al 2 O 3 composite by precipitation of the size- controlled palladium nanoparticles with the narrow size distribution from the colloidal solution. The composites were characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) methods.
Result: The size and the size distribution of the nanoparticles supported on γ-Al 2 O 3 were found increasing upon precipitation due to the Pd/γ-Al 2 O 3 strong interaction. A significant enlargement of the supported nanoparticles occurs at 300 °C. The aggregation of the nanoparticles is observed at temperatures above 500 °C resulting in increasing their size.
Conclusion: Our findings are not only applicable for a preparation of the model Pd supported on the γ- Al 2 O 3 catalyst but could be applicable for designing the Pd-containing catalyst for important industrial high-temperature processes.