One of the promising methods for process intensification for micromixing, co-precipitation, and crystallization in continuous reactors is the use of vigorous vortices. A combination of the high intensity of the kinetic energy input with the small volume of the micromixing volume allows to concentrate the energy dissipation rate up to 10⁴ W/kg and more. As the embodiment of such an idea, four new types of microreactors with intensively swirled flows were created and studied as a tool for continuous co-precipitation and crystallization. A correlation between residence time and segregation index was found: the smaller residence time, the higher energy dissipation rate and better quality of micromixing. A method for the synthesis of oxides of a number of transition metals in microreactors with intensively swirled flows with subsequent thermal treatment of co-precipitation products has been developed. This method was used to obtain ensembles of nanosized particles of zirconium oxides, as well as calcium and strontium fluorides. In comparison with the currently widely used hydro- and solvothermal methods, the proposed method has high productivity (around 10 m³/day for lab scale device), can significantly reduce the duration of the process, provides low energy consumption, does not require a large number of labor-intensive operations, is technologically advanced and easily scalable.

Using the liquid-phase methods of synthesis—the coprecipitation of hydroxides and the hydrothermal method—mesoporous xerogels are obtained based on the ZrО2–Y2О3–CeО2system with 5–8-nm particles and...

The technology of liquid-phase synthesis of mesoporous xerogels and aerogels based on ZrO₂–Y₂O₃–CeO₂ is developed. Xerogels are obtained by the coprecipitation of hydroxides, while aerogels are obtained in accordance with the sol–gel technology: the average pore size is 1.5–17.2 nm and the specific surface area is 120–878 m²/g. Aerogels are characterized by a high degree of porosity: the pore volume attains 1–4 cm³/g. Based on precursor xerogels, nanopowders of a tetragonal solid solution of the (ZrО₂)_0.92(Y₂О₃)_0.03(CeО₂)_0.05 composition with a particle size of 5–9 nm and S_spec = 74 m²/g were fabricated. Due to the high values of their specific surface area, the synthesized xerogels and aerogels are promising as sorbents, catalysts, or catalyst supports.

Xerogels in the ZrO₂–Y₂O₃–CeO₂ system are obtained by coprecipitation. The influence of the synthesis method on the acid-base xerogel surface properties are studied. The sinuous dependence of the Lewis and Brønsted site content on the particle surface on the conditioning time of precipitates in the mother liquor and the presence of subsequent low-temperature processing is established. The relationship is established between the resulting ceramics properties, precipitate processing conditions, and the functional xerogel structure.

— Xerogels in the ZrO2(Y2O3)–Al2O3system are obtained by the coprecipitation method followed by a low-temperature treatment at –25°C for 24 h. The physicochemical properties of the powders...

Nanopowders of the compositions BaHf_{1 – x}Yb_xO_3 – δ (x = 0.04, 0.08, 0.10) and BaCe_{0.9 – x}Zr_xY_0.1O_3 – δ (x = 0, 0.5, 0.6, 0.7, 0.8) were synthesized by the combined crystallization of nitric acid salts and the citrate-nitrate method. Those nanopowders were used to produce ceramic materials with a cubic crystal structure of the perovskite type, with a grain size of ~20–70 nm. The study of electrophysical properties revealed that they have a proton type of conductivity in the temperature range of 500–700°C; σ = 10^–2–10^–5 S/cm. The type and mechanism of electrical conductivity of ceramics of the composition BaHf_{1 – x}Yb_xO_{3 – δ} (x = 0.04, 0.08, 0.10) were studied both experimentally and using theoretical calculations by computer modeling using the electron density functional method; the results are in good agreement. The research shows the prospects of using the obtained ceramic materials as proton-conducting electrolytes for solid oxide fuel cells.