The catalytic properties of ultrafine nickel powder with a specific surface area of 11.7 m2/g and an average crystallite size of 34 nm, which was obtained by combining dc electrolysis and high-voltage discharge, were determined. The resulting nickel powder was used as a nanoheterogeneous catalyst in the hydrogenation of anthracene and phenanthrene. The degrees of conversion obtained with the use of the ultrafine nickel powder were compared with the values obtained using a commercial iron–chromium catalyst STK-1 (83.0% Fe2O3, 7.5% Cr2O3, and 2.0% CuO) under the same conditions. It was found that the highest conversion of anthracene in the process of hydrogenation for 60 min at a temperature of 450°C and a hydrogen pressure of 3 MPa was 86.24% in the presence of the nickel powder obtained or 91.35% with the use of STK-1. In the hydrogenation of phenanthrene for 60 min at a temperature of 400°C and a pressure of 5 MPa, the conversion was 32.28 or 25.9% with the use of the nickel powder or STK-1, respectively.

Optimal conditions for producing ultrafine iron powder by combining the processes of electrolysis and high-voltage discharge have been determined. It has been established that the maximum current efficiency q = 97.88% is achieved at a current density of D = 10000 A/m 2 , an iron sulfate concentration of C (FeSO 4 ⋅7H 2 О) = 50 g/L, a process duration of τ = 60 min, an ammonium sulfate concentration of C ((NH 4 ) 2 SO 4 ) = 40 g/L, and a voltage of U = 8000 V. Using electron microscopy, it has been found that the obtained iron powder contains nanosized particles having the BET specific surface area of 31.5 ± 0.3 m 2 /g as determined using low-temperature nitrogen adsorption. Analysis by Mössbauer spectroscopy showed the presence of magnetically ordered phases α-Fe and γ-Fe 2 O 3 , a phase close to α-FeOOH hydroxide (goethite), and possibly a mixture of β-FeOOH (acoghanite) and γ-FeOOH (lepidocrocite). It has been found that the conversion of phenanthrene during hydrogenation for 60 min in the presence of this iron powder is higher than in the presence of the industrial iron–chromium catalyst STK-1 and reaches 32.99%.

Impact of the nanosized iron powder on the process of thermal degradation of coal tar distillate was determined by the thermogravimetric analysis. Coal tar distillate was obtained by simple distillation up to 350°C of primary coal tar from the Shubarkol deposit. Iron powder was obtained by electrochemical reduction of iron from sulfate electrolytes at simultaneous impact of high-voltage electric discharge on cathodic zone. Scanning electron microscopy showed that iron powder consists of nanosized particles (30-124 nm) forming aggregates. X-ray diffraction analysis revealed the presence of α-Fe and FeO(OH) phases. The average crystallite size determination was made using Scherrer equation and amounted to 31.7 nm. Obtained iron powder was added to the coal tar distillate in amount of 1% of distillate weight and this mixture was subjected to thermal degradation at heating rate 5°C/min in an inert atmosphere. Processing of the data obtained was carried out using the model-fitting Coats-Redfern method. The values of activation energy were calculated from the linear approximation constructed as a result of processing thermoanalytical data. It was found that the addition of iron powder in amount of 1% to the coal tar distillate reduces the activation energy from 153.98 kJ/mol to 84.48 kJ/mol.

Regularities of influence of nickel nanopowder on the thermal degradation of coal tar distillate were deter-mined using model-free Kissinger, Flynn-Wall-Ozawa and model-fitting Coats-Redfern methods. Coal tar distillate with a boiling point of <350 °C was obtained by simple distillation of primary coal tar from the Shubarkol deposit. Nickel nanopowder was used as a catalyst and was added to coal tar distillate in a quantity of 1 % of the mass of the distillate and then the process of thermal degradation of coal tar distillate was con-ducted at heating rates 5, 10 and 20 °C/min in an inert gas medium. Nickel powder was obtained by high-voltage discharge impact on the dc electrolysis. X-ray diffraction (XRD) analysis showed that the obtained nickel powder has face-centered cubic structure and the average crystallite size calculated by the Scherrer equation was ~ 34 nm. Calculations of activation energy were performed via processing of thermogravimetric data. The Kissinger method showed that the activation energy value decreases from 145.19 kJ/mol to 43.65 kJ/mol, by the Flynn-Wall-Ozawa (FWO) method the value decreases from 152.82 kJ/mol to 51.65 kJ/mol, and by the Coats-Redfern method the value decreases from 143.38 kJ/mol to 52.64 kJ/mol. Ap-plicability of these methods is ensured by the high values of correlation coefficients.

The article deals with a possibility of the copper phosphide synthesis by interaction of copper (II) oxide and elemental phosphorus in the water solutions. The method of multifactorial experiment planning was used for more complete assessment of the influence of various factors on the copper phosphide yield, in particular, the concentration of phosphoric acid, the solution temperature, the process duration, the stirring rate and the weight ratio of copper oxide and phosphorus. The target product was identified by the chemical, X-ray phase and electron-optical analyses. Based on the experimental data, taking into account the significant particular functions, a multifactorial generalized equation for the output of copper phosphide was obtained. The equation is used to find the optimal conditions for the copper phosphide synthesis. The partial point dependences of the product yield on the studied factors show that they have a real impact on the process, and the mathematical models are adequate. The yield of copper phosphide is 95.1 %, which is in good agreement with the calculated data (96.5 %). The proposed method of obtaining copper phosphide in interacting of elemental phosphorus with copper (II) oxide in aqueous solutions can be used for industrial large-tonnage synthesis of copper phosphide and phosphoric acid. In this case, the proposed method does not involve appreciable costs for the production re-equipment.

The possibility of obtaining nanosized nickel powder by simultaneous dc electrolysis and high-voltage spark discharge has been explored. The powder has been prepared from a nickel sulfate-containing electrolyte using soluble nickel anodes at a cathodic current density in the range of 11000–19000 A/m2, a voltage on the spark gap of 12–16 kV, and a pulse repetition frequency of 0.5 Hz. The effect of various factors on the synthesis of the powder has been studied and the optimum conditions for its preparation have been found using mathematical experiment design. The size distribution of particles has been determined with a particle size analyzer. The BET specific surface area of the powder has been measured to be 11.7 ± 2.1 m2/g.

The results of the hydrogenation of anthracene in ethanol in the presence of different catalysts (the nanosized powders of Fe, Cu, and β-FeOOH and Ni and Fe supported on carbon microspheres) are reported. The greatest catalytic effect was observed upon the introduction of 1.5% Fe nanopowder.

В работе приведены результаты гидрогенизации антрацена в среде этанола в присутствии различных катализаторов: наноразмерные порошки Fe, Cu, β-FeOOH; нанесенные на угольные микросферы Ni, Fe. Наибольший каталитический эффект наблюдается при введении нанопорошка Fe в количестве 1.5%.

By the method of multifactor planning of experiment the laws of behavior of tellurate ions at the cathode were studied under electrolysis with simultaneous exposure on the process a highvoltage pulse discharge. For the first time it was established that multiply charged anion of tellurium electrochemically reduced to elemental state in the regime of high-voltage pulse discharge with high current output. The process takes place in one step at room temperature. Size of obtained elemental tellurium powder ranges from 41-88 nm.

The influence of different factors on the electrolytic precipitation of metallic Rhenium was investigated by the method of the mathematical planning. The mathematical model of the process was received. Optimum parameters of carrying out of electrolysis were determined.