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The influence of the dry (in the air, without water) and wet (in water) method of brown coal grinding on the extraction efficiency and structural group composition of the extracted humic acids (HA) was studied. The samples of liquid and powder humic preparations (HP) from brown coal of the Tisulskoye deposit (Kaychakskiy site) were produced. The samples were obtained using the original set-up, which allowed us to achieve the high yield of HA using ultrafine grinding of the raw material in the dry form or in the aqueous solution of an alkali. The technical characteristics and regimes of equipment operation are presented. All the samples were characterized by means of technical and elemental analysis, ¹³C NMR (CPMAS) and FTIR spectroscopy. Granulometric composition and specific surface area of coal samples after dry and wet grinding were determined. It was established that the wet method allows achieving more complete extraction of HA from brown coal due to an increase in the surface area of the contact between coal and the alkali. Both methods of grinding do not have a significant effect on the structural group composition of extracted HA and their biological activity.

The activity of monometallic (Ni/γ-Al₂O₃, Co/γ-Al₂O₃) and bimetallic (Ni-Co/γ-Al₂O₃) catalysts supported on γ-aluminium oxide for dry reforming of methane into synthesis gas was studied. It was determined that the bimetallic catalyst is more active than monometallic. A set of methods (X-ray phase analysis and temperature-programmed reduction with hydrogen) was applied to reveal that the addition of Co to the composition of Ni/γ-Al₂O₃ leads to the formation of a surface bimetallic alloy Ni-Co, which plays an important role in suppressing the formation of carbon deposits on the catalyst surface and increasing its activity.

Preparation and properties of nanostructured composites promising for the development of electrode materials for supercapacitors are considered. The composites are based on carbon fibres made of multiwalled carbon nanotubes (MCNT), filled with the nanoparticles of mixed cobalt and nickel hydroxides which are deposited on the surface and in the channels of these nanotubes. The composition and morphology of nanostructured composites were studied using transmission electron microscopy and X-ray diffractometry, including the method of small-angle X-ray scattering and X-ray fluorescence analysis. The electrochemical properties of the obtained electrode nanocomposite material were considered. It is shown that variations of the cobalt to nickel ratio in the composition of the mixed hydroxide lead to significant changes in the electrochemical properties of composite electrodes. In general, an increase in their capacitance is due to the contribution of the pseudocapacity of nickel-cobalt hydroxides, and the highest capacitance values are achieved with the Co/Ni ratio close to 1 : 1. Analysis of voltammetric curves also revealed a decrease in the specific electric capacity of the electrode material with an increase in scanning rate for samples having a pseudocapacity component, which was obtained by matrix functionalization and the introduction of cobalt and nickel hydroxides, because redox reactions on the electrodes proceed with lower rates than charge accumulation due to the double electrical layer. The functionalization of carbon nanofibres consisting of multilayer carbon nanotubes was carried out by ozonation, followed by the introduction of a hydroxide filler containing transition metal hydroxides. This treatment caused an increase in their specific electric capacity, thus it is promising for the development of highly efficient electrode materials based on carbon matrices.

The texture characteristics of carbon sorbents obtained from coal of five different grades from Kuzbass were studied. The sorbents were prepared through alkaline activation using potassium hydroxide. The alkali-coal mixture was homogenized by mechanical mixing at the KOH/coal mass ratio of 1 : 1. It was shown that the sorbents prepared from coal activated with KOH have a developed porous structure and pronounced microporosity. The structure of micropores is practically independent of coal grade. The contribution from mesopores into the porosity of the sorbents is insignificant and is observed only for fat coal. It was established that the specific surface and pore volume of the sorbents increase with a decrease in the degree of coal metamorphism. The sorbent prepared from subbituminous coal has the highest textural characteristics: its specific surface area is 1340 m²/g, pore volume 0.58 cm³/g. The minimal values are characteristic of lean coal: 780 m²/g and 0.33 cm³/g, respectively.

The synthesis of nanostructured systems based on transition metals and the investigation of their physicochemical properties is one of the urgent problems of material science given the expanding area for the application of these materials. The paper presents the results of the voltammetric study of potentiostatic electrodeposition and anodic oxidation of iron-nickel and iron-cobalt nanostructured systems with glassy carbon electrodes in various electrolytes. It was found that the electrolytic synthesis of these nanostructured systems free of oxide-hydroxide impurities can be carried out in sulphate, ammonia-tartrate and chloride media. According to the voltammetry data, the phases of solid solutions with variable composition are formed during the deposition process, and their anodic dissolution proceeds by the uniform mechanism. Metal deposition rates were compared, and an approach allowing one to calculate the compositions of electrodeposited nanostructured alloys was proposed. The capabilities of anodic and cyclic voltammetry in the characterization of nanometallic deposits were shown.

Structural, morphological and electrochemical properties of the electrode material for supercapacitors which consists of a porous matrix with embedded mixed cobalt-nickel oxide nanoparticles were investigated. The synthesis of nanostructured composite was carried out by thermal decomposition of mixed nickel and cobalt azides on the surface of multi-wall carbon nanotubes. X-ray diffraction analysis and small-angle scattering were used to determine the composition and to estimate the dispersion characteristics of the obtained oxide nanoparticles. Investigation of the electrochemical properties of synthesized electrode materials by means of cyclic voltammetry showed that the growth of their electrical capacity is proportional to an increase in the content of nickel cobaltate NiCo₂O₄ in the composite, while the dependence for cobalt oxide Co₃O₄ is more complicated. Electrode materials based on nanostructured carbon - nickel cobaltate composite С/NiCo₂O₄ provide a significant increase in electrical capacity, compared to the capacity of the original carbon matrix.

The absorption capacity of different types of coal from the largest deposits of West Siberia (Kansk-Achinsk, Kuznetsk and Gorlovskiy basins), composition and content of biogenic elements in the form of cations (K⁺, Na⁺, Ca²⁺ and Mg²⁺) in water-soluble and exchange forms are studied. It is shown that the absorption capacity of coal, as measured by cation exchange capacity, increases with an increase in the coal metamorphism degree in the sequence: anthracite → coal → brown coal, and with an increase in dispersity of carbon particles from coarse size fractions to smaller ones. The major exchange positions in coal are occupied mainly by calcium, which, in turn, negatively affects the ability of coal to participate in the exchange processes with other biogenic elements. The ability of coal to absorb cations from solutions is largely determined not by the geologically caused density and porosity of coal but mainly by the total surface area of particles. The values of the cation exchange capacity of coal are comparable with the values for the most fertile soils of West Siberia (agrochernozems) and their parent rocks (loess-like loam) or even exceed them.

The data on the effect of ozonation on the component composition and chemical properties of spent mineral engine oil are presented. It is shown that as a result of ozonolytic treatment, the relative content of aromatic and unsaturated compounds decreases in the composition of the waste oil, with an increase in the proportion of low-boiling components in the form of alkyl, alkyl ether and alicyclic structures. The content of aliphatic carboxylic acids, ethers and esters with linear and cyclic structure, lactones and anhydrides, which replenish the composition of resinous products, increases. The possibility of waste oil purification from mechanical impurities and resinous products by ozonation was revealed, and the optimal process conditions were determined, which correspond to ozone consumption of about 11 g/kg. The products of ozonation of the used engine oil - purified oil, resins, mineral deposits - can be reused in chemical, petrochemical and construction branches of industry as raw materials or their components.

Nanostructured composites Mn_xO_y/multiwalled carbon nanotubes (MCNT) with a mass ratio of Mn/MCNT 2 : 98; 5 : 95; 10 : 90 were prepared by the reduction of KMnO₄ aqueous solution on the surface of a carbon material (matrix) at a temperature of 25, 60 and 80 °C. Non-ozonized MCNT-1 and ozonized MCNT-2 were used as the carbon matrix. Nanocomposites were studied by means of X-ray phase analysis, small-angle scattering of X-ray radiation, and a complex of electrochemical methods. The influence of the conditions for producing nanocomposites (temperature, ultrasonic radiation) and the filler content on their electrical capacity characteristics were considered. It was determined that the optimal Mn/MCNT ratio was 5 : 95; with an increase in the content of manganese oxides (Mn/MCNT up to 10 : 90) and potential scanning rate higher than 40 mV/s, the electric capacitance of some samples was lower than that of the initial carbon nanotubes. For samples containing non-ozonized multiwalled nanotubes, the highest capacitance was observed for materials obtained at 80 °C; for ozonized samples, the optimum synthesis temperature was 60 °C. For optimized composition and conditions for the preparation of samples, the specific electric capacitance in asymmetric cells exceeds the specific electric capacitance of the electrodes based on the initial matrices by a factor of 1.5-2.9. Using the methods of galvanostatic charge-discharge and impedancemetry, it was established that electrochemical cells with nanocomposite electrodes have a higher capacitance and low internal resistance. It was discovered that sonication of the reaction medium during the preparation of nanocomposites leads to deterioration in the electrical capacity characteristics and to a noticeable increase in the internal resistance of the cells, especially the active component of the impedance.

A comprehensive study of the functional and group compositions of hexane-insoluble coal-tar pitch asphaltenes was carried out by chemical elemental analysis, nuclear magnetic resonance (NMR), infrared spectroscopy (IRS), and thermal analysis, and gas chromatography in combination with mass spectrometry. It was shown that the hydrocarbon skeleton of an average hypothetical asphaltene macromolecule can be considered as a set of condensed aromatic nuclei of the re-condensed type containing 7 rings, which have alkyl substituents and connecting bridges, consisting of 2 carbon atoms on average. Moreover, the structure contains one S, N, or O atom on average per 500, 50, or 167 carbon atoms, respectively, and one hydrogen atom per 2 carbon atoms. The ratio of various structural units in the powder of asphaltenes is as follows: there are 4-5 N- and 1.3-1.7 O-containing structures per one S-containing structure. Sulphur atoms are present in thiophene-like, thermally stable fragments of the structure, and pass into the coke residue without decomposition. Oxygen is in thermally unstable carboxyl and phenolic groups decomposing with the evolution of CO₂, as well as in aromatic esters passing into the coke residue. The data obtained using different methods are in good agreement with each other and will allow modeling the structural unit of coal tar-pitch asphaltene macromolecule.