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This research explores the potential of electric field enforcement in dielectric barrier discharge using specially designed pyramid‐shaped μ‐electrodes for a plasma‐assisted nitrogen fixation process. The obtained results are compared under varying conditions, including the presence and absence of titanium dioxide (TiO2 ${TiO_2 }$), different oxygen concentrations in the nitrogen‐feeding gas, and residence time. The results demonstrate that the μ‐electrodes lead to an enhancement of nitrogen oxidation, which is further intensified by TiO2 ${TiO_2 }$. The introduction of 60–70 % oxygen with nitrogen achieves the highest level of NOX ${NO_X }$ production. The synergistic effect of plasma and the catalytic effect of TiO2 ${TiO_2 }$ increase the rate of NOX ${NO_X }$ production by 20 %, resulting in a 23 % increase in energy yield. The introduction of TiO2 ${TiO_2 }$ leads to a sharp increase in NOX ${NO_X }$ production even at lower oxygen concentrations. The crucial role played by ultraviolet light‐induced electron‐hole pairs in TiO2 ${TiO_2 }$ is highlighted to promote nitrogen oxidation. Nevertheless, it is crucial to emphasize that prolonged residence times may cause the photocatalytic effect to generate alternative byproducts rather than NOX ${NO_X }$ , consequence of excessive oxidation that could prove counterproductive. These findings emphasize the potential of plasma‐assisted nitrogen fixation technology in reducing energy costs and meeting the growing demand for sustainable nitrogen‐based fertilizers. [ABSTRACT FROM AUTHOR]

This work is devoted to the investigation of the possibility of the use of Ru-containing catalysts on the basis of polymeric matrix of hypercrosslinked polystyrene (HPS) in the hydrogenation of levulinic acid (LA) to gamma-valerolactone (GVL). HPS-based Ru-containing catalysts were synthesized at variation of HPS type (MN100 bearing amino groups or MN270 without functional groups) and metal content. Catalyst 5%-Ru/MN100 was shown to compete with commercial 5%-Ru/C and to allow carrying out the hydrogenation of LA in aqueous medium with high yields of GVL (more than 99%).

The scale-up of a radiofrequency (RF) heated micro trickle bed reactor for hydrogenation of 2-methyl-3-butyne-2-ol (MBY) over a Pd/TiO2 catalyst has been performed. The axial and radial temperature profiles were calculated using a 2D convection and conduction heat transfer model. The effect of the reactor length, tube diameter and number of parallel tubes on the temperature non-uniformity parameter has been studied. The axial scale-up was achieved by repeating a single periodic unit consisting of one heating and one catalytic zone along the reactor length. The catalyst loading can be increased by an order of magnitude following this approach. A radial temperature difference of 2 K was developed in a reactor with an inner diameter of 15 mm. The scale-up by numbering up allows the accommodation of seven parallel tubes inside a single RF coil. It creates a 7 K difference in the average temperature between the central and the outer tubes which results in a 5% difference in MBY conversion. An overall scale-up factor of near 700 is achieved which corresponds to a production rate of 0.5 kg of product/day.

The CO2 splitting reaction has been investigated in a plate-to-plate micro DBD reactor with a high voltage electrode having pyramid charge injection points. The presence of sharp points (pyramids) creates zones with enhanced electric field around them. The minimum discharge voltage in the pyramid micro DBD reactor reduced from 6.5 to 5.2 kV (peak-to-peak). At the same time, the CO2 conversion increased 1.5 times as compared to that in the reactor with a flat electrode. Lowering the discharge gap from 0.50 to 0.25 mm resulted in more intense microdischarges, further increasing CO2 conversion by 1.3 times. At the same time, the energy efficiency increased further by 1.3 times. There exists an optimum residence time of 0.5 ms as a result of an interplay between plasma contact time and flow non-uniformity. The highest energy efficiency of 20% was obtained at a 3 W power, achieving a CO2 conversion of 16%. [ABSTRACT FROM AUTHOR]