Fluorite-like solid solutions of Ce0.9Sn0.1O2 and Ce0.8Sn0.1Zr0.1O2 are synthesized by co-precipitation using ammonium carbonate as a precipitant. The samples were characterized by X-ray phase analysis, electron microscopy, energy dispersive analysis, low-temperature nitrogen adsorption, and gas chromatography. It is shown that the formation of solid solutions occurs even at an annealing temperature of 550°C. In this case, the formation of lamellar particles occurs, the size of which, according to SEM data, is 4 μm. The synthesized materials have a mesoporous structure. The specific surface area of Ce0.9Sn0.1O2 samples is 80.6 m2/g, Ce0.8Zr0.1Sn0.1O2 is 76.3 m2/g. Carrying out the calcination at a temperature of 800 °C leads to an increase in the particle size up to 8 – 10 µm. The highest specific surface area of 15.3 m2/g is typical for the Ce0.8Zr0.1Sn0.1O2 sample, which is due to the presence of zirconium ions in its composition. The synthesized compositions demonstrated high activity in CO oxidation. The maximum catalytic activity was observed for the bicomponent system Ce0.9Sn0.1O2: T50% — 180°C, T90% — 236 °C. For samples calcined at a temperature of 800 °C, the most active is Ce0.8Zr0.1Sn0.1O2, which is due to the formation of a more thermally stable system compared to cerium dioxide and Ce0.9Sn0.1O2. To increase the thermal stability, it is advisable to dope the bicomponent composition Ce0.9Sn0.1O2 with Zr+4 ions.

Highly dispersed solid solutions Mn0.20Ce0.80O2-delta and M0.05Mn0.15Ce0.80O2-delta, where M = Cu, Bi, were prepared by coprecipitation followed by heat treatment. The materials were characterized by X-ray diffraction analysis, energy-dispersive X-ray spectroscopy, low-temperature nitrogen adsorption, transmission electron microscopy, and gas chromatography. The compounds prepared exhibit high activity in complete oxidation of methane. The solid solutions show promise as palladium supports. The 0.5% PdO/Mn0.20Ce0.80O2-delta and 0.5% PdO/Cu0.05Mn0.15Ce0.80O2-delta samples synthesized surpass in the catalytic activity the reference catalyst 0.5 PdO/gamma-Al2O3. Thus, it is appropriate to use the complex oxide formulations as supports of the active component.

Highly dispersed MnOx–CeO2 and MnOx–ZrO2–CeO2 catalysts for the carbon monoxide oxidation reaction are synthesized. Using the XRF and the XRD methods, the formation of the Mn–Ce–O and the Mn–Zr–Ce–O solid solutions, as well as the presence of Mn2O3 and Mn3O4, is established. The specific surface area of the synthesized materials is 121 and 155 m2/g, respectively, the particle size being equal to 8–10 nm. The X-ray photoelectron (XPS) spectra is deconvolved and the relative content of the ionic forms of Mn, the lattice oxygen Oα, and the high-energy forms Oβ are determined. Upon studying the thermal stability of catalysts, it is established that the two-component systems have low thermal stability, causing the particle size to increase to 32 nm, the specific surface area to decrease to 29 m2/g, and thus the catalytic activity to deteriorate. For MnOx–ZrO2–CeO2, less significant changes take place: the particle size is 27 nm, the specific surface area is 43 m2/g, and thus its catalytic activity is higher than that for MnOx–CeO2. Investigation of the state of the components of the near-surface layer of catalysts after isothermal aging makes it possible to ascertain the change in content of ionic forms of Mn, Oα, and Oβ. It is concluded that doping of the two-component MnOx–CeO2 systems with the Zr4+ ions is expedient. The resulting ZrO2–MnOx–CeO2 solid solution is more resistant to high temperatures.

Nanodispersed SnO2–CeO2 catalysts for the oxidation of CO and СН4 were synthesized by coprecipitation in a water–isopropanol solution followed by thermal treatment. It was shown that SnхCe1–хO2 solid solutions based on the crystal lattice of cerium dioxide were formed at x ≤ 0.15. The samples were characterized by energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), nitrogen adsorption–desorption, and gas chromatography. The materials had a mesoporous structure: the specific surface area was 52.3–69.7 m2/g, and the total pore volume was 0.073–0.108 cm3/g. When the SnO2 content was greater than 30 mol %, plate-shaped SnO2 particles with sizes greater than 100 nm were formed along with nearly spherical solid solution particles of size 8–10 nm. The synthesized solid solutions were highly active in the oxidation reactions of CO and methane, and they can be used as catalysts and supports.

Method of coprecipitation with a subsequent thermal treatment was used to synthesize highly dispersed Mn2O3-Bi2O3-ZrO2-CeO2 solid solutions. The elemental and phase compositions, texture characteristics, dispersity, and morphology were examined. The thus synthesized samples exhibit a high activity in the reaction of CO oxidation. It was shown that the nature of doping ions (Bi3+, Nd3+, Sn3+, Gd3+) affects the catalytic activity of the materials. The highest catalytic activity was observed for the Gd0.05Bi0.05Zr0.18Ce0.72O2 sample.

The formation particulars and thermal stability of nanodisperse systems MnO x –CeO2 were investigated. The composition, structure, charge state, and porosity of the obtained systems were investigated by XPA, XPS, TEM HT-XRD, XRF, and low-temperature adsorption of nitrogen.