The effect of the tungsten oxide content in Pt/WO3-ZrO2 catalysts over the range of 10–35 wt.% on hydroisomerization of the heptanebenzene mixture (80/20, wt.%) was studied. The catalysts with the WO3 content of 15–25 wt.% were shown to have the highest fraction of the tetragonal zirconia phase (t-ZrO2, 87–96%), which allows achieving the highest yield of the sum of heptane isomers, particularly high-octane di- and trimethyl substituted isomers (DTMS), the yield of which reaches 69.4–76.7 and 24.5–27.9 wt.%, respectively. In the presence of such catalysts, the yield of methylcyclopentane is 52.1–61.3 wt.% at the 72.6–90.9 % selectivity of cyclohexane isomerization to methylcyclopentane.

The effect of 0.3 wt.% indium, which was introduced at the steps of alumina peptization or impregnation, on the properties of platinumalumina reforming catalysts was studied. Doping with indium at the impregnation step produced a smaller decrease in the total acidity of the support and hence in the heptane conversion for the corresponding Pt/In/Al2O3-Cl catalyst. The most pronounced decrease in selectivity of hydrogenolysis and hydrocracking and the maximum i-C5-7 : toluene selectivity ratio were observed for this sample as compared to the undoped catalysts with indium introduction at the peptization step.

This is the second part of a series of reviews devoted to the direct synthesis of organotin compounds. This review considers conditions and results of the interaction between metallic tin and halogenoalkanes. Different catalysts used in the synthesis are systematized, their efficiency is analyzed, and possible mechanisms of these processes are discussed.

Polyfunctional Ni, Mo-containing catalysts were synthesized by sequential impregnation of the support (SiO2, Al2O3, B2O3-Al2O3, SO42–/Al2O3,SO42–/ZrO2) with solutions of the corresponding salts with intermediate drying at 120 °C and calcination at 500–550 °C. Physicochemical properties of the synthesized catalysts were studied by XRD, H2-TPR, UV-vis spectroscopy and EPR; the catalysts were tested in the singlestep synthesis of propylene from ethylene at atmospheric pressure, temperature 200 °С, and ethylene mass flow rate 0.5 h–1. The maximum values of ethylene conversion and propylene yield were observed for the sample synthesized from borate-containing alumina; this is related to the formation of active sites of ethylene dimerization – the Ni2+ cations bound to acid sites of the support, and active sites of metathesis – the surface monomolybdate compounds.

The study considers the effect of iron and manganese introduction on the textural characteristics and phase composition of the alumina matrix used as a support for sulfated zirconia catalysts in hexane isomerization. The additives introduced during plasticization of aluminum hydroxide essentially enhance the catalytic activity, which is expressed in terms of hexane conversion, and the selectivity of isomerization toward the formation of hexane isomers. The distinctive feature of the doped catalysts is the formation of acid sites with LAS/BAS ≥ 2, which promote an increase in the yield of isomers and particularly the yield of high-octane 2,2-dimethylbutane.

The study considers the effect of fluorine doping of the alumina matrix used for the synthesis of supported sulfated zirconia catalysts. Hydrofluoric acid served as a fluorinating agent. The addition of fluorine was shown to affect the textural characteristics of the Al2O3 matrix and hence the surface area of sulfated zirconia catalysts based on the doped systems. It was found that the introduction of fluorine into the catalysts increases their activity (the conversion of hexane) and the yield of high-octane isomer 2,2-dimethylbutane.

In order to elucidate the effect exerted by the addition of four-charged cations on the composition, chemical stability and catalytic properties, samples of potassium polyferrites with the β′′-alumina type structure of the composition K2FeII1+qFeIII10–2q MeqIVO17, where Me is Ce, Ti, Zr, and q = 0÷1.0, were synthesized. The mechanism of the effect of four-charged cations on the activity, selectivity of action and corrosion resistance of β′′-potassium polyferrite has been determined. Polyferrites doped with four-charged cations are characterized by a decrease in the specific rate of styrene formation and an increase in the selectivity of action in the ethylbenzene dehydrogenation reaction. The destabilizing effect of titanium additives is revealed, which is expressed in facilitating the emission of an alkali metal from the crystal lattice of polyferrite. Cerium additives lead to the destruction of the polyferrite structure due to the reduction of Ce4+ → Се3+ at the q parameter values above 0.6. Zirconium additives do not reduce the corrosion resistance of ferrite systems under the conditions of the dehydrogenation reaction.

The full article will be published in the English version of the  journal "Catalysis in Industry" No. 4, 2021.

Hydrogenation of CO2 to CO and hydrocarbons is carried out over a wide range of catalysts. Group of VIIIB transition metals have proved high conversion and selectively for CO and methane. Meanwhile, low cost and effective catalysts are preferable in an industrial scale. In this work, the synergistic effect of iron content on the catalytic performance were investigated in carbon dioxide hydrogenation reaction. Incipient wetness impregnation procedure was used for the preparation of four γ-Al2O3 supported iron-based catalysts. BET, XRD, H2-TPR and TEM techniques were employed for the catalyst characterization. The evaluation of catalysts were carried out in a fixed bed reactor at the process conditions of temperature of 300 °C, pressure of 20 atm, H2 to CO2 ratio of 3 and GHSV of 3 nl.h–1·gCat–1. It was found that the promoter addition improves the activity of Fe catalyst for both Fischer – Tropsch synthesis (FTS) and Reverse Water Gas Shift (RWGS) reactions. The results showed that conversion of CO2 was from 15.6 to 35.6 % with major products of methane, C2 to C4, C5+ and CO. It was also found that impact of K and Ce promoters into iron catalyst showed the highest conversion and hydrocarbon yield due to the synergistic effect.

The full article will be published in the English version of the  journal "Catalysis in Industry" No. 4, 2021.

Oxygenated products from selective hydrocarbon oxidation have high commercial value as industrial feedstocks. One of the most important industrial processes is the cyclohexane oxidation to produce cyclohexanol and cyclohexanone. These organic substances have special importance in the Nylon manufacture as well as building blocks for a variety of commercially useful products. In this work we present the synthesis and characterization of a new mononuclear piperazine-derived series of iron(III) complexes and their catalytic activity towards cyclohexane oxidation essays. All complexes present octahedral high-spin iron(III) center according to elemental analysis, FTIR, UV-VIS and Mössbauer spectroscopy characterization. The cyclohexane oxidation resulted in cyclohexanol, cyclohexanone and cyclohexyl hydroperoxide as products, with yields up to 39 %. The best results were obtained with the complex (NH4)[Fe(BPPZ)Cl2] (BPPZ: lithium 1,4-bis-(propanoate) piperazine) and with hydrogen peroxide as oxidant. The reactions were carried out at room temperature and atmospheric pressure, which incomes a great advantage over the current industrial process of cyclohexane production.

Aldol condensation of formaldehyde with dihydroxyacetone (DHA) in an aqueous medium (pH 7.54–8.71) was studied at 65–80 °C in the presence of zeolite-like zinc imidazolate frameworks based on 2-methylimidazole (ZIF-8) and 2-ethylimidazole (MAF-5 and MAF-6). Selectivity of the process was shown to depend on the pH of the reaction solution, which is controlled by the amount of catalyst in the reaction mixture, and on the reaction temperature. The reaction carried out at pH 8.36 and 80 °C leads to a high yield of С6-sugars. Erythrulose is formed with a high yield (39–60 %) at a temperature of 65 °C and pH 7.54-8.71. It was found that the yield of erythrulose in the presence of the catalytic systems under consideration depends on the pore radius and increases in the series MAF-6 > MAF-5 > ZIF-8. Advantages of the studied systems in comparison with the homogeneous and heterogeneous phosphate systems proposed in the literature were revealed.