THE EFFECT OF NANOSCALE SAMPLES OF SILVER AND POLVOXOMETALATE (Mo72Fe30) ON THE REACTIONS OF PEROXIDATION OF ORGANIC COMPOUNDS

Nanoscale catalytic systems are interesting from the point of view of their application in the field of ecology, organic synthesis, in particular, in redox reactions, where high catalytic activity is required using small amounts of a catalyst. Such reactions are often advisable to implement in liquid media or solutions. The high specific surface area of nanostructured materials has a positive effect on the catalytic activity in cases where their sufficient wettability and contact with a liquid substrate are ensured. When using the above-mentioned catalysts, for this reason, it is necessary to find optimal conditions for the implementation of target reactions in order to prevent possible processes of agglomeration and deactivation of catalytic systems. The different chemical nature of catalytic materials has a very significant effect on the selectivity of oxidation processes in relation to different substances. Therefore, in principle, it is possible to create catalysts that selectively oxidize certain compounds in complex mixtures. The article presents the results of studying the kinetics of liquid-phase catalytic oxidation of water-soluble organic substances by peroxide compounds in the presence of a nanoscale sample of metallic silver, nanocluster polyoxometalate (Mo72Fe30), heterogeneous iron molybdate and highly dispersed bronze powder of the PBVD brand. Phenol and ethylene glycol were used as model organic substances, the conversion of which was determined during the reaction by gas chromatography with a flame ionization detector, and saturated solutions of potassium persulfate and 36% hydrogen peroxide were used as oxidizing agents. For the catalyst samples that showed the highest substrate conversion, the reaction rate constants were calculated using the Origin program using the pseudo-first order equation. Some oxidation products have also been identified using a mass spectroscopic detector. Porous spherical nanocluster polyoxometalate Mo72Fe30 turns out to be a more effective catalyst for the oxidation of phenol with persulfate in alcoholic solutions, compared with Fe2(MoO4)3. Among the studied catalysts of liquid-phase peroxidation of ethylene glycol, colloidal silver has the greatest catalytic effect on the oxidation process.