Recently, due to the depletion of hydrocarbon fuel reserves, considerable attention has been paid to the development of effective methods for the synthesis of biofuel and biodiesel fuel, including from renewable sources of raw materials. However, the high cost of biodiesel production requires the development of new technological approaches. This has led to the active development in chemistry and chemical technology of the use of microchannel technologies for the synthesis of biodiesel fuel. The use of microchannel (MC) reactors contributes to the intensification and safety of chemical processes, which leads to economic and environmental benefits for the chemical industry. The miniature dimensions of MC reactors make it possible to save materials during their manufacture, as well as resources during operation. The increased values of heat and mass transfer in MC channels contribute to a significant increase in the productivity of MC reactors, exceeding the productivity of classical reactors in industry by 1-2 orders of magnitude. This review analyzes the literature for 2020-2024 on the use of microchannel technologies for the synthesis of biodiesel fuel. Particular attention has been paid to the advantages and disadvantages of MC reactors, as well as the main trends in their development.

Catalytic propane dehydrogenation is the targeted and most efficient industrial method of propylene production. The practical significance of this method is growing given the relative availability of propane as a feedstock. The review considered the prospects of developing new generation propane dehydrogenation catalysts based on transition metal oxides (Zn, Ga, Co and V), which can compete with commercial platinum- and chromium-containing catalysts. The review will announce a series of publications on this topic as part of the scientific research supported by the Russian Science Foundation.

 Experiments were conducted on the decomposition of formic acid on carbon nanofibers (CNFs) to produce pure hydrogen. It has been shown that carbon nanofibers are capable of decomposing formic acid predominantly with the formation of hydrogen and carbon dioxide. Alkaline treatment of CNF leads to a sharp increase in catalytic activity in the decomposition of formic acid. Treatment of CNF with alkali slightly increases the selectivity of the decomposition reaction of formic acid with the formation of hydrogen and CO₂. Using high-resolution transmission microscopy (HRTEM), it was found that alkaline treatment leads to modification of the CNF surface by sodium ions, which are uniformly distributed over the carbon surface. For comparison, the catalytic properties of CNF (NaOH) and 0.2% Pt/CNF catalysts in the decomposition of formic acid were studied. It was found that the activity of the 0.2%Pt/CNF catalyst is slightly higher than the activity and selectivity of the CNF (NaOH) catalyst.

High-temperature oxidation of NH₃ to NO on platinum alloy gauzes is employed for industrial production of HNO₃. The annual world output of HNO₃ reaches 70−80 million tons. About 80% of the produced acid is used to obtain agricultural mineral fertilizers. The oxidation of NH₃ on platinum alloy gauzes is accompanied by the formation of etching layers, which deteriorate the strength and activity of the gauzes and increase the catalyst losses. Such etching layers are being studied intensely to find ways for enhancing the efficiency of catalysts applied in the industrial oxidation of NH₃. This study deals with the morphology, microstructure and chemical composition of the etching structures on the industrial Pt−Pd−Rh−Ru gauzes with the composition 81, 15, 3.5, 0.5 wt.%, which were used in the oxidation of NH₃ with air at T = 1133 К and pressure 3.6 bar in industrial and laboratory reactors. The etching layer detected on such gauzes included “cauliflower”-type porous crystal agglomerates with the size of 10−50 µm, various crystal fragments and the wire surface with a high concentration of defects. The etching layers have an increased specific surface area, stable crystal structure and phase composition, elevated concentration of absorbed O_ab and N_ab atoms (20−25 at.%) in subsurface layers of the catalyst, and nonuniform distribution of temperature regions. The highly exothermic NH₃ oxidation reaction results in the emergence of “hotspot”-type etching sites, which form temperature gradients both on the surface and in the layer of agglomerates. The formation of such gradients can lead to the mass transfer of metals from “hot” to “cold” regions of the catalyst during the surface diffusion of metal atoms as well as upon evaporation and condensation of PtO₂-type volatile oxides leading to deep surface etching with the formation of a rough layer of “cauliflowers”.

The paper presents an approach to the conditioning of associated petroleum or natural gas. The method is based on the process of catalytic pyrolysis of light hydrocarbons С₁-С₄ on multicomponent alloy particles. As a result of such a process it is possible to obtain mainly a mixture of СH₄+H₂, since it is the fraction of С₂-С₄ that is subjected to pyrolysis with the formation of hydrogen and carbon nanofibers (CNF). Equiatomic alloy [CoFeNi] promoted by addition of 7 at.% Cu ([CoFeNi]Cu₇) shows the highest activity in decomposition of C₂-C₄ mixture. The maximum yield of CNF at 650 °C was 106 g/g_cat in 30 min. It is shown that such an alloy can be successfully used for catalytic decomposition of С₂-С₄ fraction in a mixture with methane. The dependence of CNF yield on the concentration of С₂-С₄ fraction in the model mixture has been determined. It was found that at pyrolysis of the mixture with the volume ratio С₂-С₄/СH₄ = 10/90 within 30-180 min there is no appreciable deactivation of the catalyst. The yield of CNF after 180 min of reaction was 160 g/g_cat. The average conversion of the С₂-С₄ fraction in one pass reaches 20 %. The morphology and structure of the obtained CNF were studied by scanning and transmission electron microscopy and low-temperature nitrogen adsorption.

A dynamics of the reaction of non-oxidative methane coupling at 600⁰C catalyzed by 1%Pt/MgAlOх and 1%Pt/g-Al₂O₃ with close size of platinum clusters has been studied. In contrast to reference 1%Pt/g-Al₂O₃ sample, carbonaceous strongly adsorbed compounds accumulated during reaction running can be burnt out completely in 1%Pt/MgAlOх catalysts at the same temperature, which restored their catalytic activity.  A possibility to increase the duration of their operation with maximal C2-C3 products yield under cyclic mode and minimal CO and CO₂ formation during regeneration has been shown.

The catalytic properties of supported Pt-containing granular (Pt/Ce_0.75Zr_0.25O₂) and structured (Pt/Ce_0.75Zr_0.25O_2-δ/η-Al₂O₃/FeCrAl) catalysts for methanol steam reformong to syngas were studied and compared. Comparative studies prove that the active Pt/Ce_0.75Zr_0.25O₂ system in the structured catalyst operates more efficiently than in the granular catalyst. In particular, the structured catalyst 0.15 wt. % Pt/8 wt. % Ce_0.75Zr_0.25O_2-δ/6 wt. % η-Al₂O₃/FeCrAl at atmospheric pressure, temperature 400 °C, and the reaction mixture (30 vol. % CH₃OH, 35 vol. % H₂O, 35 vol. % N₂) feed rate of 60 L/(g_cat·h), provided complete conversion of methanol to syngas with a total H₂ and CO content of ~60 vol. % and syngas productivity of ~85 L(H₂+CO)/(g_cat·h).