The fine crystal structure of hematite samples used to prepare potassium-promoted iron oxide dehydrogenation catalysts has been studied by X-ray diffraction and scanning electron microscopy. Samples of α-Fe2O3 were obtained under nonequilibrium conditions from several precursors under different thermolysis regimes. The most important characteristic of hematite, which determines the activity and selectivity of the catalyst based on it, is the fine crystal structure (TCS). The TCS of hematite determines the phase composition of the catalyst. The TCS of hematite is formed during the synthesis of hematite and is determined by the nature of the precursor, the temperature of sample synthesis, and the temperature gradient of the rate of removal of gaseous thermolysis products. The highest activity was demonstrated by a catalyst prepared on the basis of hematite with mosaic blocks of 70–90 nm, with a minimum concentration of SF due to half and quaternary dislocations. Such hematite was obtained by thermolysis of iron sulfate at 950 K under fluidized bed conditions and a low temperature gradient. Hematite from iron carbonate is not recommended for the synthesis of a catalyst due to the high concentration of low-temperature SF, which leads to the formation of catalytically inactive potassium β-polyferrite.

Hydrogen accumulation, storage and production systems are the important direction in the development of fundamental and applied aspects of alternative energy. Liquid organic hydrogen carriers (LOHC), polycyclic forms of the corresponding aromatic compounds, are an efficient way of hydrogen storage and release with a hydrogen content of up to 7.3 mas.%. This article compares LOHC as potential substrates for hydrogen storage and hydrogen evolution based on catalytic hydrogenation-dehydrogenation reactions, including cyclohexane, methylcyclohexane, decalin, perhydroterphenyl, bicyclohexyl, perhydrodibenzyltoluene and perhydroethylcarbazole. For each of the perhydrogenated substrates, data on the activity and selectivity of Pt-containing dehydrogenation catalysts are presented.

The full text of the article will be published in the English version of the journal "Catalysis in Industry" No. 1, 2023.

One of a widely-used broad-spectrum industrial bactericidal and mildew prevention agents is 1,2-benzoisothiazolin-3-one (BIT). In present study, it was demonstrated that aerobic oxidative cyclization of 2-mercaptobenzamide (MBA) and 2,2’-disulfanediyldibenzamide (DSBA) in the presence of Mn(OAc)2 as catalyst allowed to obtain BIT. The mechanism reaction was suggested. It was found that DSBA and MBA can be converted to the BTI with 99 % yield at 1.0 mol.% Mn(OAc)2 under 0.3 MPa of O2 and 100 °C for 8 h. Experimental data point that this protocol is both economical and environmentally friendly.

The paper describes ways for controlling the molecular structure of polyethylene (PE) produced over supported catalysts containing bis(imino)pyridyl complexes of Fe(II) (LFeCl2) and bis(imine) complexes of Ni(II) (*LFeCl2), which are anchored on silica gel modified by the introduction of alumina (SiO2(Al)). Under variation of polymerization conditions over LFeCl2 /SiO2(Al) catalysts, linear PE with different molecular weight and controllable molecular-weight distribution (MWD) was obtained. Homopolymerization of ethylene over *LNiBr2 /SiO2(Al) catalysts led to the formation of branched PE with the molecular-weight and thermophysical characteristics close to the low-density polyethylene produced by ethylene copolymerization with α-olefins over supported metallocene catalysts and supported Zieglertype catalysts. A method was proposed for constructing the supported bicomponent catalysts containing LFeCl2 and *LNiBr2 complexes anchored on the SiO2(Al) support for the deliberate production of polyethylene with the required molecular structure. There are examples of obtaining the linear PE with bimodal MWD on a bicomponent supported catalyst containing two different LFeCl2 complexes, the PE with controllable branching distribution on a bicomponent catalyst synthesized by anchoring LFeCl2 and *LNiBr2 complexes on the SiO2(Al) support, and an example of modifying the industrial chromium oxide catalyst by introducing the LFeCl2 complex for the control of MWD and branching distribution in the produced polyethylene.

Thermochemical properties of molecules and thermodynamic characteristics of vacuum distillate hydrotreatment were calculated by quantumchemical methods. A kinetic model of the hydrotreatment process was developed using a formalized transformation scheme of hydrocarbons. The developed kinetic model was employed in numerical studies aimed to estimate the effect of the feedstock composition on the residual content of heteroatomic components in the product of vacuum gas oil hydrotreatment, the effect of temperature on the content of aromatic hydrocarbons, nitrogen and sulfur in the hydrotreatment product, and the effect of the hydrogen-containing gas consumption on the content of sulfur and hydrogen sulfide in the hydrotreated vacuum gas oil.

A phenol–tetralin model mixture was used to investigate the effect of the oxygen-containing compound on the cracking of aromatic hydrocarbon. The analysis of temperature dependences of the cracking rate constant for tetralin and tetralin in a mixture with phenol indicates that the cracking of tetralin is hindered in the case of its simultaneous conversion with the oxygen-containing compound due to higher adsorptivity of phenol on the catalyst surface. It was found that the presence of phenol in the model mixture changes the composition of liquid products, especially at a low cracking temperature. In addition, the effect of water on conversion of the phenol–tetralin mixture was studied. The presence of water in the model feedstock was shown to decrease the hindering of the aromatic hydrocarbon cracking by the oxygencontaining compound. The results of catalytic transformations revealed that the addition of water increased total conversion of the mixture and conversion of tetralin irrespective of temperature. Essential qualitative differences in the distribution of cracking products of the model mixtures containing or not containing water were not found.

The paper summarizes the experience in the development of a microspherical chromium-alumina catalyst for isobutane dehydrogenation to isobutylene according to the technology devised at Yarsintez. The development of commercial catalysts of the KDI series based on a new boehmite support was considered. Interrelations of elemental and phase composition of the catalysts with their performance were established. A new two-step scheme for producing the boehmite support by hydrothermal treatment of the thermal decomposition product of gibbsite agglomerates with a desired size makes it possible to control its phase composition as well as the physico-mechanical characteristics of the catalysts and their catalytic properties, which allowed obtaining a series of KDI, KDI-M, and KDI-M1 catalysts. The most important steps in commercial implementation of the catalyst at PJSC Nizhnekamskneftekhim were noted. The commercial KDI-M catalyst provided a stable 33–37 % yield of isobutylene in isobutane dehydrogenation and a 30 % yield of methylbutenes in isopentane dehydrogenation. The catalyst consumption was 2–3 kg per ton of the produced isobutylene. The catalyst operation was monitored to propose a way for its improvement and optimization of the reactor instrumentation. According to the laboratory testing, a commercial sample of the KDI-M1 catalyst modified with a silicon-containing inorganic complex compound has higher activity and selectivity than previous catalysts of this series and is ready to industrial implementation.

It was shown that sorbite can be obtained from potato starch by its single-step hydrolysis-reduction in the presence of bifunctional catalysts 0.3–3 wt.%Ru/Cs3HSiW12O40 (Ru/Cs-HPA). Most efficient was the catalyst containing 1 wt.%Ru; this is related to the optimal concentration ratio of Broensted and Lewis acid sites on the support surface and a high specific surface area. The reaction kinetics in the presence of 1%Ru/Сs-HPA was studied and the apparent activation energy of the starch hydrolysis-reduction to sorbite (80±8 kJ/mol) was determined. The experimental and literature data were used to propose a kinetic model of the process, which describes quite adequately the hydrolysisreduction of starch. In the presence of the catalyst with the optimal composition (1%Ru/Cs-HPA) at the optimal temperature (150 °С), the yield of sorbite achieved 88 mol.% (99 wt.%) for 3 hours of the reaction.