In this work, results of the synthesis of bimetallic nanoparticles (NPs) based on transition metals Pd, Ni, and Fe reduced by quercetin in reverse-micellar solution (RMS) of Н 2 О/AOT/isooctane are presented. Using fluorescence spectroscopy, the formation of bimetallic structure of Pd core Ni shell NP is shown and a synergetic enhancement of optical absorbance is revealed in the plasmon resonance spectra at the wavelength values intrinsic for monometallic NPs. Investigation of the adsorption of bimetallic NPs on the surface of γ-alumina proves the advantage of palladium-containing particles with Fe core /Pd shell obtained as a result of targeted reduction of palladium in RMS on the surface of large Fe NPs, which appears in the increase in the adsorption effectiveness of such a structure due to stronger binding with the carrier surface. This approach decreases the amount of expensive metal during production of palladium nanocomposites through a significant decrease in production costs.

— Synthesis of bimetallic nanoparticles (NPs) of the transition metals Rh and Pd in H 2 O/AOT/isooctane (where AOT is dioctyl sodium sulfosuccinate) reverse-micelle solutions (RMSs) in the presence of molecular oxygen and quercetin, a flavonoid, is described. The methods for NP synthesis used here enable us to prepare alloyed-type Rh−Pd NPs and core/shell Pd/Rh and Rh/Pd NPs with the metal molar ratio of 1 : 1. With both Rh 3+ and Pd 2+ ions present in an RMS simultaneously, palladium ions are reduced first, and the formed Pd NPs have an inhibitive effect on reduction of rhodium ions. The stability of a mixture of Rh and Pd NPs in RMSs is investigated, and the mixture of NPs with a mean diameter of ~2.7 nm is found to be stable for at least 25 days. Pd and Rh NP-based catalysts are prepared by absorption of the synthesized NPs on γ-Al 2 O 3 , and their catalytic activity is tested in the monomolecular hydrogen isotope exchange reaction. A synergetic effect, manifested as an enhanced catalytic activity, is observed for the catalyst prepared by adsorption of the mixture of Rh and Pd NPs on γ-Al 2 O 3 .

In this paper, the results of the adsorption and catalytic properties of the mono- and bimetallic palladium and rhodium nanoparticles (0.7–6.5 nm) impregnated on γ-Al2O3 were presented. Metal nanoparticles were obtained in reverse micelles by two reduction methods: radiation-chemical and chemical reduction of ions. Three types of bimetallic nanoparticles Rhcore/Pdshell, Pdcore/Rhshell and substitution alloy Rh-Pd were obtained. The isotope exchange H2+D2⇄2HD and the conversion ortho-H2⇄para-H2 reactions were used as model catalytic processes. It was found that with increasing ω=[H2O]/[surfactant] in addition to increasing the size of the formed particles, also the ratio of particle sizes in a micellar system changes, and in systems with a high value ω, the formation of fine particles is observed. The BMNPs of Rhcore/Pdshell type, showing a synergistic effect in the catalytic properties of reactions involving molecular hydrogen, were obtained [Ks(Rhcore/Pdshell)>4 Ks (Rh or Pd)]. The dependence of the catalytic activity for Rh and Pd NPs on their sizes was obtained. The catalytic activity of the NPs increases with their diameters in the studied range of sizes. The phenomenon of aggregation (sintering) of Rh NPs at a temperature of 800°C was observed. Reflected attempt to compare the optical absorption spectra with the type of nanoparticles.

It has been established that the size of metal nanoparticles affects the adsorption properties and catalytic activity of deposited palladium catalysts used in H2-D2 exchange reactions and ortho-para protium conversion reactions. Nanoparticles have been obtained by radiation-chemical reduction from reversemicellar solutions. The structure and size of the prepared palladium nanoparticles have been studied.

In this work, the method of UV-VIS spectrophotometry was used to study the adsorption of palladium nanoparticles Pd NPs on silicon dioxide (silochrome S-120). Pd NPs were synthesized using a radiation-chemical method in micelle 0.15 M solutions of the AOT surfactant at different degrees of hydration ω 0 = [H 2 O]/[AOT]. It is shown that adsorption depends on the structure of nanoparticles, conditions of synthesis in reverse micelles, including the ω 0 value, which determines the NP size, as well as the chemical and physicochemical properties of the silochrome surface.