FORMATION OF Ru NANO-COMPOSITES

Abstract

Researches of polymer immobilized nanoparticles of ruthenium have been carried out by frontal polymerization (FP) of ruthenium acrylonitrile (AN) complex in the presence of inorganic carrier. Assessment of their catalytic properties in the hydrogenation reaction of unsaturated compounds has been done. Effective and selective organo-inorganic catalyst has been synthesized on the basis of akrylonitril complex and its reactivity in the hydrogenation reaction of cyclohexen has been investigated. Synthesis of akrylonitril complex of ruthenium on the surface of mineral carrier SiO2 silica, its further polymerization and reduction leads to the formation of polymer-inorganic composite including nano-size particle of Ru stabilized by polymer matrix and inorganic carrier. The offered method is a new approach in the catalyst preparing. Synthesized samples of Ru- nano composetes have been studied by methods of element analysis, IR-spectroscopy and X-ray analysis. There are wide diffraction peaks at 300-800 °C range in the X-rays patterns of the obtained samples wich correspond to crystallic ruthenium. Broadening diffraction maximums testifies ultradisperse state of particles. Microporous structure with pore sizes to 20 nm and their uniform size distribution are typical for obtained nano composites. It has been determined that specific surface of carriers decreases after polymerization of RuAN on the surface, though it is bigger than S spec. of the polymerization product in SiO2 absence. Obtained hybride nano composites have developed surface and porous structure which provide accessibility of active centers of catalyst for reagents and their high activity in the researched catalytic reaction. Formation conditions of Ru nanoparticles influence on catalytic properties of the studied composites, for example, the use of various regimes of frontal polymerization in inert medium. With the increase of the reduction treatment temperature of nano-composites the hydrogenation rate of cyclohexene reduces, the reason of which is the integration of Ru particles in the obtaining of nano composites at high temperatures. It should be mentioned that after hydrogenation the main ruthenium mass in poly-RuAN (90%) will have zero valency. The polymer matrix reduces. It is also subjected to changes and it confirms by spectrum broadening. Thus, the synthesized hybridization of polymer-immobilized Ru-nanoparticles display high activity in the reaction of cyclohexene hydrogenation and keep their activity during repeated cycles of reactions. Catalytic properties of nano-composites depend on the conditions of their obtaining which influence apparently on the size of forming Ruthenium nanoparticles.Forcitation:Agaguseynova M.M., Mikailova M.R. Formation of Ru nano-composites. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2018. V. 61. N 3. P. 45-50