Effective Catalytic Reduction of Methyl Orange Catalyzed by the Encapsulated Random Alloy Palladium-Gold Nanoparticles Dendrimer

A series of stable and well-dispersed random alloy nanoparticles of palladium and gold was synthesized by a template method using dendrimers. The synthesized nanoparticles were qualitatively and quantitatively characterized by UV-Vis spectrophotometry (UV-Vis), High-resolution transmission electron spectroscopy (HR-TEM), energy dispersed X-ray spectroscopy (EDS) and inductively coupled plasma optical emission spectrometry (ICP-OES). Metal nanoparticles size (Pd55Au55/Dens-OH ((2.21 +/- 0.41) nm)) were significantly close to the calculated nanoparticles size (Pd55Au55/Dens-OH (2.59 nm)). Catalytic reduction of methyl orange was performed as a model reaction in the presence of sodium borohydride. The kinetic investigation was monitored through a microplate reader. The obtained data were kinetically interpreted according to the Langmuir-Hinshelwood approach. The catalytic process described an exothermic process, where the model compound physicochemical adsorption on the nanoparticles active surface site was found to be a non-spontaneous process.