The purpose of this work was to create magnetic nanocatalysts that could be used for the oxidation of organic water pollutants – phenol and its derivatives – and to determine the physicochemical characteristics of the catalysts. The development of such active nanocomposite catalysts would solve the environmental problem in the Republic of Kazakhstan in the field of wastewater treatment from organic impurities, including phenols, and would also contribute to the subsequent creation of domestic production of oxygen-containing compounds, since almost the entire spectrum of oxygen-containing compounds for various industries is imported into the Republic. Nanosized magnetic composites based on Fe and Co were obtained by chemical deposition, in some cases, using polyethyleneimine and polyvinylpyrrolidone. It was shown that the interaction between nanoparticles and the polymer takes place in the case of a CoFe2O4 catalyst stabilized with polyvinylpyrrolidone or polyethyleneimine, which may indicate the efficient formation of nanocomposites. According to the IR study, for the CoFe2O4 nanocomposite stabilized with polyvinylpyrrolidone, the absorption bands at 735, 663, 649, 626 cm–1 are natural vibrations for the composite nanoparticles embedded in a polyvinylpyrrolidone matrix. The synthesized nanocomposites were tested in the oxidation of phenol with oxygen. The results demonstrate that the catalysts are promising both for the purification of industrial wastewater from phenol and for the synthesis of oxygen-containing compounds in the liquid phase under mild conditions.

The development of new catalytic systems based on cobalt and iron compounds for the production of oxygen-containing compounds is an urgent task of chemical technology. The purpose of this work is the synthesis of CoFe₂O₄ stabilized with polyvinylpyrrolidone (PVP), the study of the catalyst by physico-chemical research methods, and the determination of the effectiveness of the CoFe₂O₄/PVP catalyst in the phenol oxidation reaction. In this work, magnetic composites CoFe₂O₄ and CoFe₂O₄ stabilized with polyvinylpyrrolidone were synthesized by co-deposition. A comparison of the characteristics of the properties of the synthesized cobalt (II) ferrite (CoFe₂O₄) and the composite material CoFe₂O₄/PVP based on it is carried out. The obtained samples were examined using X-ray phase analysis (XRD), the Debye–Scherrer method, scanning electron microscopy (SEM), Mossbauer and IR Fourier spectroscopy, as well as thermogravimetric analysis (TGA). The textural properties were determined based on the analysis of nitrogen isotherms. The catalytic properties of the synthesized materials in the process of phenol oxidation in the presence of hydrogen peroxide are considered. The analysis of the reaction mixtures by HPLC obtained by the oxidation of phenol in the presence of a CoFe₂O₄/PVP catalyst showed a decrease in the concentration of phenol in the first 15 min of the process (by 55–60%), and then within 30 min, the concentration of phenol decreased to 21.83%. After 2 h of the process, the conversion of phenol was already more than 95%. The final sample after the reaction contained 28% hydroquinone and 50% benzoquinone. It was found that the synthesized magnetic composites exhibit catalytic activity in this process.

It is known that highly efficient catalysts for the catalytic oxidation of aromatic hydrocarbons can be obtained based on magnetic nanoparticles. The development of nanosized magnetically controlled catalysts for the oxidation of aromatic hydrocarbons with oxygen deserves especially close attention in the territory of the Republic of Kazakhstan, which does not have its own industrial production of oxygen-containing compounds. The aim of this work is to create catalysts based on Fe and Co nanoparticles stabilized with polymers: polyvinylpyrrolidone, chitosan, and polyethylenimine, study them by methods of physico-chemical research, and conduct preliminary tests of catalysts to predict their effectiveness. Magnetic nanoparticles were prepared by the co-precipitation method. Based on the results of the SEM analysis, it was concluded that polymers form composites together with metal nanocrystals. According to preliminary data, the most efficient oxidation of phenol in a non-flowing glass gradient-free thermostated duck-type reactor occurs on Fe₃O₄/chitosan, with the phenol conversion being 55–60%. Tests on the oxidation of phenol with oxygen showed a favorable prognosis for the use of such catalysts for the oxidative conversion of aromatic hydrocarbons in order to obtain valuable intermediates.