The Sr2TiO4 samples were synthesized by mechanical activation (MA) from a mixture of SrCO3 and TiO2 precursors followed by calcination at 900 and 1100 degrees C. The accumulation of internal energy stresses in the mechanical mixture of precursors was controlled by varying the mechanical activation time (10, 20 and 25 min) through the use of mills of different power. Powder mixtures of precursors as-blend, after MA, and after calcinations were studied using XRD, FTIR, thermal analysis, and SBET methods. The energy impact in Sr2TiO4 synthesis is more pronounced at calcination temperature of 900 degrees C, the increase in the energy load at a temperature of 1100 degrees C is levelled out, due to the formation of practically single-phase Sr2TiO4.

The La0.9Sr0.1Sc0.9Co0.1O3-delta (LS) and La0.9Sr0.1CoO3-delta (LC) phases and composite materials based on them were synthesized. There are data in the literature on the activity of pure or modified forms of LC in ammonia decomposition, but there are no data on the activity of the LS phase and LS-LC composites. Therefore, the stability and activity of LS-LC composites and initial LS and LC in ammonia decomposition were investigated. The best result in the decomposition of ammonia at 700 degrees C and WHSV of 60000 ml NH3.g(cat)(-1).h(-1) shows LC - 99%, the worst LS - 80%. Under the same conditions, the activity of samples LC, 40LS-60LC and 50LS-50LC remains unchanged for 40 hours. It was found that during ammonia decomposition, the LC phase decomposes to form cobalt and La(OH)(3) nanoparticles, but the LS phase does not undergo significant changes, which is confirmed by X-ray diffraction, IR spectroscopy, Raman spectroscopy and TEM.

The La 1– x Ca x Mn 0.5 Co 0.5 O 3 solid solutions ( x = 0.2-0.6) are prepared by the Pechini method and characterized by a number of physical and chemical methods. It is shown that the oxygen nonstoichiometry in the samples significantly increases with increasing number of calcium cations in the La sublattice. The thermal analysis of the samples shows that the lattice oxygen is released at ~600 °C for all samples and that its amount increases with increasing calcium content. The in situ powder XRD data obtained in the He atmosphere indicate that the studied solid solutions with x ≥ 0.4 are unstable under these conditions and may exhibit partial structural destruction and that the AB O 3 complex oxide in the system with x = 0.6 transforms into a phase characterized by the A 2 B O 4 structural type of the Ruddlesden–Popper series.

A concept of a high throughput, user-friendly, versatile bending magnet beamline at the fourth-generation synchrotron radiation facility SKIF, currently being constructed in Koltsovo (a science town near Novosibirsk, Russia), is proposed. The beamline is designed to implement the conventional and most demanded synchrotron techniques: XAS (X-ray absorption spectroscopy); XRD (X-ray diffraction), both powder and single-crystal, including the in situ mode; and XRF (X-ray fluorescence analysis). The beamline is conceived to be as simple as possible, but it is multifunctional, being a base beamline for the education and training of students, future synchrotron users, and beamline scientists. A number of potential beamline optical layouts are modeled in the XRT (XRayTracer) program package. The resulting beam characteristics at the sample position are discussed. A monochromator model is proposed. Surface distortions and their influence on the rocking curve of the Si111 crystal due to incoming heat loads are realistically modeled. The optimum design of the station is defined. The range of crystalline objects that are possible to be studied at the proposed station is emphasized, and future perspectives are outlined.

A theoretical analysis of diffraction patterns was performed for two representatives of layered perovskite-type tetragonal phases of the Ruddlesden-Popper series (RP) with the general formula A(n+1)B(n)O(3n+1) (n = 1, 2), which contain RP faults (layer alternation defects) in a wide range of concentrations. The results of theoretical calculations can be used in the future for correct interpretation of X-ray powder diffraction experimental data and for quantitative estimation of the deviation from stoichiometry and structural perfection of this type of compound.

Single-walled carbon nanotubes (SWCNTs) are promising materials for use in multifunctional polymer composites. A special feature of SWCNTs is their tendency to aggregate into bundles with 2D close packing. The coherence of such packing leads to the appearance of diffraction maxima at small-angle X-ray scattering. Using the Debye equation for X-ray scattering, this work presents the results of a theoretical analysis of the influence exerted by various parameters of SWCNT bundles (length and diameter of SWCNTs, transverse dimensions of SWCNT bundles, distribution of diameters and the number of SWCNTs in bundles) on the position, width, and shape of these diffraction peaks. To this end, atomic models of both the individual tubes and their bundles were constructed taking into account the diameter distribution of nanotubes, which has a significant effect. The results obtained can be used to correctly interpret the experimental diffraction data.

The products of mechanically stimulated interaction of NiO with Al were studied by X-ray diffraction and IR spectroscopy. Composites Ni/α-Al2O3, NiAl/α-Al2O3, Ni2Al3/α-Al2O3 can be fabricated by varying the ratio of initial components under the selected conditions of mechanical activation. The approach under consideration, based on a mechanically stimulated reaction, makes it possible to significantly simplify the previously proposed method of mechanically activated self-propagating high-temperature synthesis and produce nanostructured composites.

The effect of gadolinium additives on the morphology, phase composition, and catalytic properties of MoVSbNbGdOx/SiO2 catalysts in the oxidative dehydrogenation of ethane to ethylene (ODE) is studied. It is shown that gadolinium concentration has a significant effect on the catalytic properties. At an optimum gadolinium content (Gd/Mo = 0.01–0.015), an increase in catalytic activity and ethylene selectivity is observed: at a temperature of 400°C, the ethylene yield achieves 72

We propose a procedure for estimating the content of layer alternation defects in A 2 B O 4 structures of the homologous Ruddlesden–Popper series by analysing the ratio of certain interplanar distances. The calibration plots are constructed from the calculated diffraction patterns using a probabilistic model of one-dimensionally disordered crystals with different concentrations of defects. The procedure is tested on Sr 2 TiO 4 samples using the synchrotron experiment data.

We present a concept design of the CCU SKIF–NSU Experimental Station 1-7 “Basic methods of synchrotron diagnostics for educational, research, and innovative activities of students” for improving the efficiency of the educational process and helping the NSU students to solve research problems using the capabilities of a modern synchrotron radiation source. Several research methods are planned to be jointly implemented at the Experimental Station 1-7: powder and single-crystal X-ray diffraction, X-ray absorption spectroscopy, and X-ray fluorescence analysis. This research complex will not only allow solving a wide range of scientific problems in various fields of science such as physics, biology, chemistry, geology, archeology and medicine, but will also become an essential element of the practical education of scientific and technical stuff for the synchrotron research.

IR spectroscopy, electron microscopy, and X-ray diffraction analysis, including the application of synchrotron radiation, have been used to study the mechanochemical reduction of copper oxide with aluminum at the stoichiometric ratio of the components and in the presence of an excess of oxide-forming metal and aluminum solid solution in copper as well. The possibility is shown of the mechanochemical reduction of copper oxide with aluminum and aluminum solid solution in copper, which is accompanied by the formation of the Сu/Al 2 O 3 composite structure. To modify copper with alumina, using an aluminum solid solution in copper is preferable.

Platinum alloy gauzes are employed for the high-temperature oxidation of NH3 to NO used in the industrial production of HNO3 for application in agricultural fertilizers. To enhance the efficiency of NH3 oxidation, various Pt–Pd–Rh alloys are employed for the production of such catalytic gauzes. To understand the role of these metals in NH3 oxidation, scanning electron microscopy, energy-dispersive spectroscopy and X-ray diffraction were applied to investigate the morphology, composition and structure of Pt, Pd and Rh foils after annealing in O2 and oxidation of NH3 with air at 1133 K. After annealing in O2 and NH3 oxidation, the metallic microgranular structure was detected on Pt(poly), whereas oxide layers of Rh2O3 and PdO were observed on Rh(poly) and Pd(poly). At the onset of NH3 oxidation (t = 1 h), fibrous metal-oxide agglomerates of nanofibers formed on these oxide layers. The long-term (5–10 h) oxidation of NH3 led to the formation of a continuous layer of pyramidal crystals on Rh(poly) and palladium “cauliflowers” on Pd(poly). The highly exothermic reaction of NH3 with oxygen on metals and PdO or Rh2O3 initiates strong catalytic etching forming grains and facets on Pt, fibrous metal-oxide agglomerates, pyramidal crystals and metallic “cauliflowers” on Rh and Pd.

The results obtained in this study show that Sb-containing catalysts MoVSbNbGdOx/SiO2 are highly active in ethane oxidative dehydrogenation to produce ethylene. The ethylene yield of 72% (79.3% ethylene selectivity and 91.1% ethane conversion) was obtained at 400 C on one of the best catalyst. The effect of Gd additives on the catalytic properties of MoVSbNbGdOx/SiO2 catalysts was investigated. The catalysts with Gd/Mo = 0.010 - 0.015 demonstrated relatively high catalytic activity coupled with high selectivity to ethylene and excellent stability in ODE reaction, but further growth of the gadolinium content (Gd/Mo = 0.02) was accompanied by the decrease in the activity and ethylene selectivity. XRD, HRTEM, SEM, XPS and adsorption methods were used to reveal the phase composition, morphology and the structure of the obtained catalysts.

Methane oxidative coupling (OCM) is considered a potential direct route to produce C2 hydrocarbons. Layered perovskite-like Sr2TiO4 is a promising OCM catalyst. Mechanochemical activation (MA) is known to be an environmentally friendly method for perovskite synthesis. Sr2TiO4 were synthesized using MA of the mixtures containing SrCO3 or SrO and TiO2 or TiO(OH)2 and annealing at 900 and 1100 °C. XRD and FT-IRS showed that MA leads to the starting component disordering and formation of SrTiO3 only for SrO being pronounced when using TiO(OH)2. After annealing at 900 °C, Sr2TiO4 was mainly produced from the mixtures of SrCO3 or SrO and TiO(OH)2. The single-phase Sr2TiO4 was only obtained from MA products containing SrCO3 after calcination at 1100 °C. The surface enrichment with Sr was observed by XPS for all samples annealed at 1100 °C depending on the MA product composition. The OCM activity of the samples correlated with the surface Sr concentration and the ratio of the surface oxygen amount in SrO and perovskite (Oo/Op). The maximal CH4 conversion and C2 yield (25.6 and 15.5% at 900 °C, respectively), and the high long-term stability were observed for the sample obtained from (SrCO3 + TiO2), showing the specific surface morphology and optimal values of the surface Sr concentration and Oo/Op ratio.

Mixed Ni-Al oxide catalytic precursors with different elemental ratios (20, 50, and 80 wt.% Ni0) were synthesized using green supercritical antisolvent co-precipitation (SAS). The obtained oxide precursors and metal catalysts were characterized in detail by X-ray diffraction (XRD) analysis, atomic pair distribution function (PDF) analysis, CO adsorption, and high-resolution transmission electron microscopy (HRTEM). It was found that the composition and structure of the Ni-Al precursors are related to the Ni content. The mixed Ni1−xAlxO oxide with NiO-based crystal structure was formed in the Ni-enriched sample, whereas the highly dispersed NiAl2O4 spinel was observed in the Al-enriched sample. The obtained metal catalysts were tested in the process of anisole H2-free hydrogenation. 2-PrOH was used as a hydrogen donor. The catalyst with 50 wt.% Ni0 demonstrated the highest activity in the hydrogenation process.

In this study, the effect produced by the gallium oxides intercalation into MnOx-Al2O3 catalysts on their catalytic properties and structural aspects of the active component formation was investigated. Three series of the catalysts, Mn-Al, Mn-Ga, and Mn-Al-Ga, having a similar Mn content but different Al/Ga ratio, were synthesized by coprecipitation and subsequent calcination at temperatures from 600 to 1200 degrees C degrees. The catalysts were tested in CO oxidation. For the Mn-Al series of catalysts, a thermal activation effect is observed, defined as an increase in catalytic activity after high-temperature treatment at 900-1000 degrees C. The increase in the activity after calcination is related to the formation of the Mn3-xAlxO4 solid solution at the synthesis temperature and its segregation upon cooling. Segregation of the solid solution leads to the formation of the Mn3O4+delta defect oxide and an amorphous aluminum-containing component. The addition of 5%Ga to the Mn-Al catalyst changes the phase transformation route during thermal activation. The in situ XRD data has showed that at 1000 degrees C the high-temperature solid solution (MnGaAl)3O4 with the cubic spinel structure is formed; however, its further segregation upon cooling is hindered. The introduction of gallium stabilizes the structure of the (MnGaAl)3O4 mixed oxide, the parent oxide is partially decomposed after cooling with Mn3O4 nanoparticles formation. However the amount of produced active Mn3O4 particles and/or weakly bound oxygen is much lower, which in turn adversely affects the catalytic properties.

Double oxides with the structure of the Ruddlesden–Popper (R-P) layered perovskite An+1BnO3n+1 attract attention as materials for various electrochemical devices, selective oxygen-permeable ceramic membranes, and catalytic oxidative reactions. In particular, Sr2TiO4 layered perovskite is considered a promising catalyst in the oxidative coupling of methane. Our high-resolution transmission electron microscopy (HRTEM) studies of Sr2TiO4 samples synthesized using various methods have shown that their structure often contains planar defects disturbing the periodicity of layer alternation. This is due to the crystal-chemical features of the R-P layered perovskite-like oxides whose structure is formed by n consecutive layers of perovskite (ABO3)n in alternating with layers of rock-salt type (AO) in various ways along the c crystallographic direction. Planar defects can arise due to a periodicity violation of the layers alternation that also leads to a violation of the synthesized phase stoichiometry. In the present work, a crystallochemical analysis of the possible structure of planar defects is carried out, structures containing defects are modeled, and the effect of such defects on the X-ray diffraction patterns of oxides of the A2BO4 type using Sr2TiO4 is established as an example. For the calculations, we used the method of constructing probabilistic models of one-dimensionally disordered structures. For the first time, the features of diffraction were established, and an approach was demonstrated for determining the concentration of layer alternation defects applicable to layered perovskite-like oxides of the A2BO4 type of any chemical composition. A relation has been established between the concentration of planar defects and the real chemical composition (nonstoichiometry) of the Sr2TiO4 phase. The presence of defects leads to the Ti enrichment of particle volume and, consequently, to the enrichment of the surface with Sr. The latter, in turn, according to the data of a number of authors, can serve as an explanation for the catalytic activity of Sr2TiO4 in the oxidative coupling of methane.

The article is devoted to the Department of Physical Methods for Solid Research of the Physics Department of Novosibirsk State University, the basic institutes of which are the Boreskov Institute of Catalysis and the Nikolaev Institute of Inorganic Chemistry of the Siberian Branch of the Russian Academy of Science. It tells about the history of the foundation of the department, its lecturers and the directions of their scientific research, and also about the disciplines studied. The reader can get acquainted with the list of department’s master’s programs and with the achievements of its graduates and the prospects for further development.