Palladium Oxide Nanoparticles

Palladium Oxide Nanoparticles

palladium oxide nanopowder were prepared in aqueous suspension with a very simple procedure, by dissolving palladium nitrate in water at a concentration around 10−4 M. UVvisible absorption spectroscopy was adopted to follow the formation of these nanoparticles, which were characterized by TEM microscopy, along with XRD, XPS and Raman measurements. DFT calculations allowed to interpret the Raman data and to clarify the species present at the surface of the nanoparticles. The catalytic activity of the latter was evaluated by monitoring the reduction of p-nitrophenol to p-aminophenol. This investigation paves the way to the use of these colloidal nanoparticles in processes of heterogeneous catalysis, in particular those concerning the catalytic degradation of aromatic derivatives that represent a serious danger for the environment as pollutants, as in the case of p-nitrophenol.

Palladium(II) oxide (PdO) has also found applications in many catalytic processes, but few studies were carried out on the production of palladium oxide nanoparticles compared to the wide range of works concerning metallic palladium particles. A problem in obtaining colloidal suspension of PdO nanoparticles derives from the agglomeration of them, so it was often necessary to introduce surfactants or supporting materials that favored their stability. In this work, we propose a simple method to obtain stable palladium oxide nanoparticles dispersed in water, without the need of additives. The characteristics of the nanoparticles have been investigated by different techniques and their catalytic activity has been evaluated by monitoring the reduction reaction of p-nitrophenol to p-aminophenol.