Aluminum oxides and hydroxides are widely applied because of the great variety of their modifications. In particular, aluminum oxides and hydroxides are used in petrochemistry and oil refining. However, amorphous aluminum compounds have not been sufficiently studied due to the complexity of their synthesis and the problems encountered during their study. The study of amorphous aluminum compounds is hindered by the ambiguity of terminology. In this work, the structures of amorphous aluminum compounds prepared by different methods and the properties that determine their applications have been highlighted in detail. Amorphous aluminum compounds play both positive and negative roles in petrochemistry; however, in petroleum refining, amorphous compounds (without promoters and transition metal salts) demonstrate a promising catalytic performance in oil upgrading.

Amorphous aluminum compounds are formed during the synthesis of the γ-Al₂O₃ catalyst precursor. Amorphous compounds influence on the alumina catalyst variously due to different physicochemical properties, which depend on the method of their preparation. In this research, the comparative analysis of physicochemical properties of amorphous aluminum compounds that were obtained by the precipitation method, the thermal decomposition of aluminum nitrate, and alcoxide hydrolysis product were studied. It is the first time that a new method for calculating of quantitative phase composition of amorphous aluminum compounds using the X-ray powder diffraction, thermogravimetric and differential scanning calorimetry analysis, mass-spectrometry, and CHN-analysis was described. Properties of obtaining samples were studied using scanning electron microscopy, low-temperature nitrogen adsorption, and temperature programmed desorption of ammonium analyses. The methods of precipitation and thermal decomposition of aluminum nitrate allows for obtaining non-porous samples consisting of a mixture of amorphous phases (hydroxide and basic salt) that contain the metals impurities and have low acidity of the oxides obtained from them. The highly porous amorphous alumina formed by the thermal decomposition of the alcoxide hydrolysis product with the least amount of impurities and a high acidity of the surface was observed.

Due to the continuously rising demand for C₃–C₅ olefins it is important to improve the performance of catalysts for dehydrogenation of light alkanes. In this work the effect of modification by SiO₂ on the properties of the alumina support and the chromia-alumina catalyst was studied. SiO₂ was introduced by impregnation of the support with a silica sol. To characterize the supports and the catalysts the following techniques were used: low-temperature nitrogen adsorption; IR-spectroscopy; magic angle spinning ²⁹Si nuclear magnetic resonance; temperature programmed desorption and reduction; UV-Vis-, Raman- and electron paramagnetic resonance (EPR)-spectroscopy. It was shown that the modifier in amounts of 2.5–7.5 wt % distributed on the support surface in the form of SiO_x-islands diminishes the interaction between the alumina support and the chromate ions (precursor of the active component). As a result, polychromates are the compounds predominantly stabilized on the surface of the modified support; under thermal activation of the catalyst and are reduced to the amorphous Cr₂O₃. This in turn leads to an increase in the activity of the catalyst in the dehydrogenation of isobutane.

The effect of 1-propanol on the transformation of the organic matter (OM) of the domanik rock of the Romashkino field with the С_оrg content of 7.26% in supercritical water (SCW) at 374°С was studied. The OM undergoes essential changes in the course of these experiments. According to the Rock-Eval data, addition of 1-propanol to the SCW reaction medium increases the rock production index (PI) by a factor of almost 2, from 0.48 to 0.76, owing to high degree of degradation of the insoluble kerogen, from 22.17 to 0.30 mg g^–1 rock (parameter S₂). A part of kerogen degradation fragments transforms into resins and aromatic compounds whose content in the extract increases by a factor of more than 2, whereas the content of saturated hydrocarbons (HCs) considerably decreases. As compared to the experiment in straight SCW, insoluble high-carbon substances of carbene/carboid type are absent. The gas phase contains 78.8 rel % СО₂, which favors the recovery of high-molecular-mass oil components from the low-permeability domanik rock. The formation of HC gases is indicative of the occurrence of intense degradation processes involving homolytic cleavage of C–C bonds by the radical-chain mechanism. The content of high-molecular-mass n-alkanes C₁₇–C₂₇, phenanthrenes, and dibenzothiophenes in the transformed shale oil increases. The structure of aromatic HCs, resins, and asphaltenes after treatment in SCW with the addition of 1-propanol becomes more condensed, and the content of aliphatic fragments and sulfoxide S=O groups decreases, suggesting the occurrence of dehydrogenation with the elimination of long alkyl chains via cleavage of heteroatomic bonds. In the process, 1-propanol not only acts as a cosolvent but also prevents the recombination of radicals formed in the course of kerogen degradation, which is confirmed by a decrease in the concentration of free radicals in resins and asphaltenes. The structurization of resins and asphaltenes leads to the removal of metals from porphyrin molecules and to a decrease in the paramagnetic properties. After the treatment both with SCW and with SCW + 1-propanol, the resins are characterized by superhyperfine splitting of the line of the vanadyl complex, caused by interaction with the ¹⁴N nuclei, which suggests transformations of alkylporphyrins into monocycloalkylporphyrins via dealkylation, demetalation, and hydrogenation. After the autoclave experiments, the structure of mica in the mineral matter of the domanike rock undergoes changes due to segregation of the separate montmorillonite phase.

The presence of χ-Al₂O₃ resulting from thermal decomposition gibbsite as part of alumina catalysts is unfavorable because of its acid characteristics. One of the available techniques of χ-Al₂O₃ removal is crystallization under hydrothermal conditions into boehmite, which is a main precursor of active γ-Al₂O₃. The influence of products of the hydrothermal treatment of χ-Al₂O₃ obtaining in result of thermal decomposition gibbsite under T = 150–200 °C, P = 0.5–1.5 MPa and pH = 4.0–9.2 were studied. The hydrothermal treatment products in these conditions are gibbsite and boehmite phases which are formed coincidently by parallel ways. In the alkaline medium at pH = 8.0–9.2 three-dimensional parallelepiped boehmite crystals with the edge length > 200 nm are formed, at pH = 4.0 two-dimensional rhombic-shaped plates with thickness 20–100 nm and with the edge length ~ 80–500 nm are formed. Crystallization of coarse boehmite particles promotes the formation of large and closed mesoporous.