CeO 2 nanooxide has been synthesized from cerium(III) nitrate using powdered cellulose (PC) and its mixture with sucrose as templates. The removal of templates from composites (PC–Ce(NO 3 ) 3 and PC–sucrose–Ce(NO 3 ) 3 ) has been carried out in two ways: via direct burning-out of PC (PC–sucrose) in an air flow and via burning-out of the carbonizate after template pyrolysis. Using UV and IR spectroscopy, X-ray powder diffraction (XRD), and electron microscopy, the influence of the template composition and the method of its removal on the physicochemical characteristics of CeO 2 nanoparticles has been studied. A carbon–oxide material CeO 2 /C has been synthesized by pyrolysis of PC–Ce(NO 3 ) 3 and PC–sucrose–Ce(NO 3 ) 3 composites. It has been established that the pyrolysis of PC–Ce(NO 3 ) 3 and PC–sucrose–Ce(NO 3 ) 3 leads to the formation, in the carbonizate, of CeO 2 (cerianite) nanoparticles with sizes of 3–4 and 1–2.5 nm, respectively. The average diameter of nanoparticles (according to XRD data) is 3.8 and 2.3 nm. CeO 2 /C synthesized from the PC–sucrose–Ce(NO 3 ) 3 composite contains cerium(III) oxide. All CeO 2 nanoparticles in the carbon matrix have a hydroxyl–hydrate cover. The burning of the organic or carbon matrix of the composites leads, regardless of the template used and synthesis conditions, to the formation of CeO 2 (cerianite) nanoparticles with the same average diameter of 25 ± 1 nm (according to XRD data), containing an admixture of the Ce(III) phase and having a hydroxyl–hydrate cover. Carbon is present in the material in trace amounts (≤0.15 wt %). The size scatter of CeO 2 nanoparticles produced by burning out PC from the PC–Ce(NO 3 ) 3 composite is 15–30 nm. In those cases when the organic component from PC–sucrose–Ce(NO 3 ) 3 is subjected to burning or the pyrolysis stage of both composites is included in the synthesis process, the appearance of a fraction of larger CeO 2 particles (50–60 nm) is observed. The correctness of the obtained data has been confirmed in the course of the model process of hydrogen peroxide decomposition.

Pyrolysis of cellulose powder granules impregnated with an aqueous solution of saccharose and palladium nitrate gave granular Pd/C carbons with 1–9 wt

CeO2 nanooxide has been synthesized from cerium(III) nitrate using powdered cellulose (PC) and its mixture with sucrose as templates. The removal of templates from composites (PC–Ce(NO3)3 and PC–sucrose–Ce(NO3)3) has been carried out in two ways: via direct burning-out of PC (PC–sucrose) in an air flow and via burning-out of the carbonizate after template pyrolysis. Using UV and IR spectroscopy, X-ray powder diffraction (XRD), and electron microscopy, the influence of the template composition and the method of its removal on the physicochemical characteristics of CeO2 nanoparticles has been studied. A carbon–oxide material CeO2/C has been synthesized by pyrolysis of PC–Ce(NO3)3 and PC–sucrose–Ce(NO3)3 composites. It has been established that the pyrolysis of PC–Ce(NO3)3 and PC–sucrose–Ce(NO3)3 leads to the formation, in the carbonizate, of CeO2 (cerianite) nanoparticles with sizes of 3–4 and 1–2.5 nm, respectively. The average diameter of nanoparticles (according to XRD data) is 3.8 and 2.3 nm. CeO2/C synthesized from the PC–sucrose–Ce(NO3)3 composite contains cerium(III) oxide. All CeO2 nanoparticles in the carbon matrix have a hydroxyl–hydrate cover. The burning of the organic or carbon matrix of the composites leads, regardless of the template used and synthesis conditions, to the formation of CeO2 (cerianite) nanoparticles with the same average diameter of 25 ± 1 nm (according to XRD data), containing an admixture of the Ce(III) phase and having a hydroxyl–hydrate cover. Carbon is present in the material in trace amounts (≤0.15 wt %). The size scatter of CeO2 nanoparticles produced by burning out PC from the PC–Ce(NO3)3 composite is 15–30 nm. In those cases when the organic component from PC–sucrose–Ce(NO3)3 is subjected to burning or the pyrolysis stage of both composites is included in the synthesis process, the appearance of a fraction of larger CeO2 particles (50–60 nm) is observed. The correctness of the obtained data has been confirmed in the course of the model process of hydrogen peroxide decomposition.

We demonstrate a few-step technique for the synthesis of PdO/TiO2 and Pd/TiO2 (0.1–2.0 wt % Pd) xerogels, which comprises hydrolysis of a palladium nitrate solution in titanium tetrabutoxide in the vapor atmosphere over an aqueous acetic acid solution, drying, and calcination of the material between 800 and 870°C. According to X-ray diffraction and electron microscopy characterization results, after calcination at 800°C the xerogels contained palladium in the form of PdO particles ≤3–5 nm in size. The highly dispersed palladium(II) oxide covered the surface of the rutile crystallites and filled pores in between. Throughout the range of Pd(NO3)2 concentrations studied, the PdO particles were identical in size. In the material calcined at 870°C, palladium had the form of metallic particles ranging in diameter from 55 to 420 nm. Raising the palladium nitrate concentration in titanium tetrabutoxide was shown to increase the average size of the Pd particles.

A concise procedure was developed for the synthesis of silver-containing xerogels Ag(0)/TiO2 [0.2–3.2 wt % Ag(0)], including the dissolution of AgNO3 in tetrabutoxytitanium, hydrolysis of the solution in acetic acid–water vapors, drying, and calcining the xerogel at 600–800°C. It was found by X-ray diffraction analysis and electron microscopy that the bulk of metallic silver particles (75–90%) in the material calcined at 800°C has a size of 25–45 nm. The fraction of particles (in the form of crystal intergrowths) with a diameter of 95–115 nm rises with an increase in the AgNO3 concentration at the dissolution stage; TiO2 is present in the rutile phase. At a calcination temperature of 600°C, the dominant TiO2 phase (72%) is anatase; in this case the size of silver particles is 5–10 nm.

A simplifi ed procedure for the synthesis of Pd 0 /TiO 2 xerogel has been developed, which includes the following steps: hydrolysis of tetrabutoxytitanium from its mixture with a palladium salt in an acetic acid atmosphere, drying and calcining the material at 860 °C. Palladium in the calcined xerogel is present in the form of spherical particles, titanium dioxide — as rutile aggregates.

Pd/TiO2–SiO2 xerogels containing 0.15–0.75 wt % palladium are prepared from Pd(NO3)2 · 2H2O solutions in a mixture of tetrabutoxytitanium (TBT) and tetraethoxysilane (TEOS) in a desiccator under acetic acid–water vapors in the batch mode at 20°С followed by drying and calcination of the material at 850°С. IR spectroscopy showed that the presence of Pd(NO3)2 · 2H2O has no effect on the amount of newly formed Ti–O–Si bonds in the double oxide TiO2–SiO2 over the range of salt concentrations studied. X-ray powder diffraction showed that palladium present in the xerogel calcined at 850°С is in the form of Pd(0) nanoparticles. The electron-microscopic morphology study showed that the items prepared (Pd(0) nanoparticles) had near-spherical shapes; their sizes fell in the range 20–230 nm. A means for varying Pd(0) nanoparticle size in the material is to vary the palladium(II) salt concentration at the dissolution stage.

Pd/TiO 2 –SiO 2 xerogels containing 0.15–0.75 wt % palladium are prepared from Pd(NO 3 ) 2 · 2H 2 O solutions in a mixture of tetrabutoxytitanium (TBT) and tetraethoxysilane (TEOS) in a desiccator under acetic acid–water vapors in the batch mode at 20°С followed by drying and calcination of the material at 850°С. IR spectroscopy showed that the presence of Pd(NO 3 ) 2 · 2H 2 O has no effect on the amount of newly formed Ti–O–Si bonds in the double oxide TiO 2 –SiO 2 over the range of salt concentrations studied. X-ray powder diffraction showed that palladium present in the xerogel calcined at 850°С is in the form of Pd(0) nanoparticles. The electron-microscopic morphology study showed that the items prepared (Pd(0) nanoparticles) had near-spherical shapes; their sizes fell in the range 20–230 nm. A means for varying Pd(0) nanoparticle size in the material is to vary the palladium(II) salt concentration at the dissolution stage.

The TiO2 and TiO2SiO2 xerogels were prepared by hydrolyzing tetrabutoxytitanium or its mixture with tetraethoxysilane. The synthesis was conducted in an acetic acidwater atmosphere under stationary conditions followed by calcinations. The final TiO2 and TiO2SiO2 xerogels represented 3D globular pore structure with a narrow globule size distribution. At hydrolysis of terabutoxytitanium, acetic acid vapors favored formation of TiO2 xerogel with a higher surface area compared to the material produced without acidic catalyst.

How the specific surface area and the amorphous-to-crystalline titania phase ratio in TiO2–SiO2 (14 mol % TiO2) xerogels change during the fivefold repeated cycles comprising the hydrogen peroxide treatment of the xerogel followed by drying and calcining of the binary material, was traced by the BET method, X-ray powder diffraction, and IR spectroscopy.

The technique of synthesis of 2,3,5-trimethyl-1,4-benzoquinon via catalytic oxidation of 2,3,6-trimethylphenol in H2O2—H2O—PhCH3 system with vibrational stirring is developed. Xerogels TiO2 and TiO2—SiO2 were used as catalysts in the process. The effect of physicochemical properties of xerogels on the course and characteristics of oxidation is studied.

ZrO 2 –SiO 2 xerogels have been synthesized through hydrolysis of a mixture of tetrabutoxyzirconium and tetraethoxysilane in a desiccator in a vapor of a 15% aqueous NH 3 atmosphere. ZrO 2 –SiO 2 –Cu(II) xerogels were synthethized analogously through joint hydrolysis of a mixture of the organometallic precursors and copper(II) chloride. The effect of synthesis conditions on the physical and chemical properties of the resulting material has been studied.

TiO2–ZrO2 binary oxides were prepared by joint hydrolysis of tetrabutoxytitanium (TBT) and tetrabutoxyzirconium (TBZ) mixtures under an atmosphere of H2O vapor and 10% aqueous NH3 in the batch mode. The physical and chemical properties of the thus-prepared samples were studied as dependent on the synthesis parameters.

Joint hydrolysis of tetrabutoxytitanium and tetraethoxysilane in a desiccator in the presence of water vapor was used to synthesize spherical granules of a TiO2-SiO2 binary xerogel with a KU-23 polymeric cation exchanger used as a matrix. Specific structural features of the resulting new form of the catalytic system were revealed. It was shown that the catalytic activity of titanium contained in the Ti-O-Si mixed amorphous phase substantially exceeds that of TiO2 in the anatase phase.