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The relevance of exploring the ways to impact the Russian Arctic schoolchildren’s attitudes towards nature is explained by the contradictions between the obvious social significance of this issue (and at the same time its wide application possibilities) and the lack of Russian researchers interested in it. Our hypothesis was that occasional visits to botanical gardens can have a significant impact on the development of personal attitudes towards nature in primary schoolchildren of the Russian Arctic. The aim of this study was to identify the specifics of environmental attitudes in a group of primary school students of the Russian Arctic region and to evaluate the impact of occasional visits to the botanical garden on these attitudes. The study involved 60 students of 2-4 grades of secondary schools of the Murmansk region and was conducted using the technique by S.D. Deryabo and V.A. Yasvin "AESOP" (Emotions, Knowledge, Protection, Benefit) on the basis of the Polar-Alpine Botanical Garden of the the N.A. Avrorin Institute of the Kola Research Center, Russian Academy of Sciences. The outcomes of the study show that primary school children living in the Russian Arctic, just like their peers from other regions, generally perceive nature as an aesthetic object. However, their perception of nature tends to have a decreased cognitive component (‘Knowledge’). We conclude that occasional visits to botanical gardens that engage children in a specially organized cognitive activity can be considered significant only in terms of the pragmatic component (‘Benefit’) of the environmental attitude.

Ordered mesoporous MgAl2O4 support was synthesized by one-pot evaporation-induced self-assembly method with block copolymers. Nanocomposite catalysts were prepared by loading this support with PrNi0.9Ru0.1O3 perovskite or Ni + Ru-doped Ce0.35Zr0.35Pr0.3O2 fluorite oxides. Their texture, structure, surface properties and reactivity have been studied by combination of modern structural, spectroscopic and kinetic methods. Suppression of MgAl2O4 support acidity, strong interaction of small Ru-Ni alloy nanoparticles with the surface layers of this support modified by perovskite and fluorite oxides with a high oxygen mobility and reactivity provide a high activity and stability to coking and sintering of these catalysts in all studied reactions of methane and ethanol transformation into syngas. Ni + Ru/Ce0.35Zr0.35Pr0.3O2/MgAl2O4 active component loaded on honeycomb Fechraloy foil substrate demonstrated a high performance and stability to coking in autothermal natural gas oxi-dry reforming, ethanol steam reforming and autothermal reforming of ethyl acetate in concentrated feeds promising for the practical application.

Modification by Nd, Mn, Ga, and Ge substantially affect both physicochemical and catalytic properties of MoVNbTeO oxides in the oxidative dehydrogenation of ethane (ODE). The introduction of modifying additives changes the content of the M1 phase, surface acidity, and surface composition. It does not have an influence on the state of Mo, V, Nb, and Te on catalyst surface, but it induces surface enrichment (Ga, Mn) or depletion (Ge, Nd) by the modifying element. All of these additives have positive effects on catalytic properties at the M/Mo (M = modifying element) ratio of 0.0075 ÷ 0.025. They exhibit an increase of activity and prevent ethylene over-oxidation. The relationship between the rate constant of total ethane transformation and the M1 content confirms that this phase is active in ODE. The correlation between ethylene selectivity and the relative number of intermediate acid sites is revealed, indicating the role of surface acidity on ethylene over-oxidation.

Silica-supported catalysts with the cationic gross composition V0.3Mo1Te0.23Nb0.12 were synthesized by the slurry method upon variation of the initial support compound (TEOS, silica sol, silica gel, aerosil). The synthesized catalysts were characterized by means of nitrogen thermal desorption, chemical and X-ray diffraction analysis, and high resolution electron microscopy. The catalytic properties were examined in oxidative dehydrogenation of ethane at a temperature of 400 °C in the reaction mixture with the composition С2Н6 : О2 : N2 = 10 : 10 : 80 (vol.%). The maximum activity was observed for the samples obtained with the use of silica gel, which is caused by the formation of nanodomains of the active phase M1 in amorphous matrix of the support and by its partial dispersion.

Mixed ionic-electronic conductors are of great interest for development of oxygen separation membranes and air electrodes for intermediate temperature solid oxide fuel and electrolysis cells. This work presents the results of studying the structure, transport properties and oxygen mobility in Nd2−xCaxNiO4 oxides (x = 0–0.5), synthesized via a solution-assisted solid state reaction method, in correlation with the over-stoichiometric oxygen content. High oxygen mobility was demonstrated in the low-doped materials (DO ~ 10−10–10−8 cm2/s at 700 °C) which corresponded to the ionic (oxygen) conductivity values ~ 10−4–10−2 S/cm, comparable to those for widely used solid electrolytes and state-of-the-art cathode materials. The polarization resistance of the Nd2−xCaxNiO4+δ electrodes in contact with Ce0.8Sm0.2O1.9 electrolyte was shown to have non-linear dependency on Ca content, which may be caused by the influence of two opposite tendencies for decreasing over-stoichiometric oxygen and oxygen diffusivity and increasing the total conductivity with Ca doping. High electrical and electrochemical characteristics along with oxygen mobility mean the materials developed display high potential for electrochemical and catalytic applications.

The ordered mesoporous Mg- and Ni-Mg-alumina samples of general formula xwt%Mg-Al2O3 and ywt%Nixwt% Mg-Al2O3(x, y = 5, 10 % wt) have been prepared by the one-pot evaporation induced self-assembly (EISA) method using Pluronic P123 as a template. The textural and structural properties of the prepared samples have been characterized by N2adsorption-desorption analysis, BET, XRD, TEM with EDX, HAADF-STEM, and H2-TPR. The samples calcined at 700°C had an ordered mesoporous structure with a SSA of 170-250 m2/g, a pore volume of 0.5-0.64 cm3/g and a narrow distribution of the pore size (mean 12-16 nm). For the catalysts prepared by the one-pot EISA method, the size of the metal Ni particles was in the range of 3-12 nm and was conditioned by their confinement in the mesopores and the interaction with MgO and Al2O3. Testing in methane dry reforming in the 15v.% CH4+ 15v.%CO2feed, with He balance, at 650-750°C and the contact time of 0.015 s has shown the higher activity and stability of the ordered mesoporous 10w%Ni- 10w%Mg-Al2O3catalysts prepared by the one-pot method as compared with the catalyst of the same composition obtained by impregnation.

Design of oxide and nanocomposite materials with high mixed protonic-electronic conductivity such as lanthanide niobates and tungstates is encouraging approach in developing hydrogen separation membranes. This work aims at elucidating the relation of structure, oxygen and protonic mobility of such materials. La0.99Ca0.01NbO4, LaNb3O9 and Nd5.5WO11.25−δ were synthesized by Pechini and citrate route. Nanocomposites with LaNb3O9 and Ni + Cu were prepared by ultrasonic dispersion or mechanical treatment in a high energy mill and wet impregnation, then sintered using conventional thermal sintering and hot pressing. All obtained materials were characterized using XRD, SEM, TEM with EDX analysis, IR and Raman spectroscopy. The oxygen and proton mobility were studied by isotope exchange, unit cell volume and weight relaxation techniques. The proton conductivity was studied by Van der Pauw technique. The main phases were scheelite for La0.99Ca0.01NbO4, perovskite for LaNb3O9 and fluorite for Nd5.5WO11.25−δ, extended defects were observed agreeing with IR and Raman spectroscopy data. The oxygen mobility studies revealed two types of bulk oxygen related to two phases in samples. D2O exchange studies demonstrated very fast protonic transport in samples. H2O desorption experiments revealed the working temperature range being 300–450 °C. The protonic conductivity values (~10−4 Ω−1 cm−1 at 400 °C) agree with the literature data and are sufficiently high for the practical application. Proton tracer and chemical diffusion coefficients values are ~10−11 and ~10−3 cm2/s at working temperatures, respectively. Successful test of proton conducting membrane with Nd5.5WO11.25−δ based functional layer showing promising performance has been carried out.

Praseodymium nickelate Pr2NiO4+δ with layered Ruddlesden–Popper (R–P) structure is a promising material for the ceramic membranes for oxygen separation and for SOFC cathodes due to its mixed ionic-electronic conducting nature and high oxygen mobility and surface reactivity. However, a low thermal stability and the inadequate electronic conductivity of Pr2NiO4+δ require its doping for a more efficient performance. This work presents results of study of the effect of Ca doping on the structural and transport properties of Pr2NiO4. Pr2−xCaxNiO4 oxides (x = 0–0.6) were synthesized by a co-precipitation method and characterized by XRD, XPS and TEM methods. The oxygen content in these materials and its variation with increasing temperature was evaluated using TGA. The oxygen transport properties of powdered samples were studied by the temperature-programmed oxygen isotope heteroexchange with C18O2 (TPIE). Electrical conductivity of compact samples was measured by a dc four-probe technique. Electrochemical measurements were performed using an impedance spectroscopy method with symmetrically arranged electrodes on the Ce0.8Sm0.2O1.9 electrolyte. It was shown that doping resulted in enhanced electrical conductivity and at a low Ca content the electrochemical activity of electrodes increased while the interstitial oxygen content and oxygen diffusivity gradually decreased. For x > 0.3 increasing the lattice anisotropy resulted in the co-existence of 2–3 channels of oxygen diffusion revealed as separate peaks in TPIE curves. The fast diffusion channel (D⁎ ~ 10−8 cm2/s at 700 °C), with a share in the total diffusion drastically decreasing at big doping levels, corresponds to the fast interstitial oxygen diffusion via the cooperative mechanism while the slow channels (D⁎

An effect of Pt addition to improve the catalytic performance of Pd-modified Mn-hexaaluminate in the high-temperature oxidation of methane, especially in SO 2 and water presence, has been studied. X-ray diffraction, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, thermogravimetry and differential thermal analysis were used for the characterization of fresh and spent catalysts. Temperature-programmed reduction by hydrogen was employed to study the redox properties of the catalysts. Four high-temperature tests (at 670 °C) of the methane oxidation were applied to reveal the water and sulfur resistance of the catalysts: 1) dry methane-air feed; 2) wet methane-air feed containing 3 wt% of water vapor; 3) methane-air feed containing 1000 ppm of SO 2 ; and 4) wet methane-air feed with 1000 ppm of SO 2 . The Pt-doped Pd-Mn-hexaaluminate catalyst with the atomic ratio of Pt/Pd 0.5. From the formal kinetic data of the oxidation of methane on the fresh and deactivated catalysts, we assumed that deactivation of the catalysts is due to a decrease in the amount of catalytically active sites in the bimetallic 0.33Pt-0.67Pd(0.27)/MnLaAl 11 O 19 catalyst and a change in the state of active component in the other catalysts. Their oxidation ability and redox behavior were shown to be associated with the highly dispersed PdO particles, a PdO layer (3–5 nm) covering the metal palladium particles as well as the Mn 3+ -enriched MnLaAl 11 O 19 . The improved water and sulfur resistance is found to correlate with the presence of particles of PtPd alloy, with its fraction not exceeding 50%.

Two series of supported Co-containing catalysts modified with La and Ce oxides were synthesized by solution combustion with different amounts of glycine. Their properties were compared with characteristics of unmodified Co catalyst and modified catalysts synthesized by impregnation in an excess of solution without glycine. XRD, TEM, UV–vis DRS and differential dissolution were employed to investigate the phase and chemical composition, morphology and localization of catalytically active particles in the support matrix. Their redox and catalytic properties were characterized using H2-TPR and kinetic experiments on the oxidation of butane. Specific surface area, particle size, chemical composition of the active component and its localization as well as the reducibility by hydrogen were shown to depend on the synthesis mode and amount of fuel additive (glycine). A higher catalytic activity of the samples obtained by solution combustion synthesis as compared to those synthesized by impregnation is caused by the enrichment of subsurface layers of the support with Co(II,III) cations in the composition of simple (Co3O4) and mixed (CoAl2O4) nanosized oxides, by an increase in specific surface area and a decrease in the particle size of the active component and promotor. It was shown that the amount of glycine has a stronger effect on the properties of the catalyst than its modification with lanthanum or cerium oxides.

For catalysts comprised of mixed manganese-chromium oxides MnxCr3-xO4 (x = 0.3–2.7) prepared by Pechini route with Ni and Ru supported by impregnation fundamental factors determining their performance in ethanol steam reforming have been elucidated using combination of structural (XRD, HRTEM), spectroscopic (UV–vis), surface science (XPS, FTIR spectroscopy of adsorbed CO) and kinetic (H2 and EtOH TPR, oxygen isotope heteroexchange with C18O2) methods. The most important feature is strong metal-support interaction stabilizing small clusters of metals/alloys and preventing carbon nucleation. The lattice oxygen mobility and reactivity increased with Mn content. The highest TOF was obtained for (Ni + Ru)–loaded oxide support containing cubic spinel phase of MnCr2O4 composition, which implies a positive effect of Ni-Ru interaction in mixed clusters on catalytic activity. This catalyst has also a high density of active sites, surface enriched by Mn and sufficient oxygen mobility providing coking stability, which makes it attractive for practical application.

Catalysts based on oxides with a high lattice oxygen mobility and reactivity are known to be able to efficiently transform ethanol into syngas by selective oxidation. Mechanism of this reaction over Pt/Pr0.15Sm0.15Ce0.35Zr0.35O2 catalyst was studied by using SSITKA and pulse microcalorimetry. The rate–determining step is CC bond rupture in ethanol/acetaldehyde molecules, while CH bond breaking in the ethanol dehydrogenation step proceeds easily. The mechanism is described by step-wise red–ox scheme including ethanol oxidative decomposition on Pt sites with participation of bridging oxygen species (with the heat of adsorption ∼ 550 kJ/mol O2) located at Pt-oxide interface followed by fast reoxidation of reduced support sites by O2. Rapid oxygen migration from the oxide sites to Pt provides conjugation between these steps, thus suppressing coking.

This work aims at elucidating effects of composition and microstructure of materials based upon Pr1-ySmyNi1-xCoxO3-δ perovskites on their oxygen mobility. Pr1-ySmyNi1-xCoxO3-δ and their composites with Y-doped ceria are perspective materials for intermediate temperature solid oxide fuel cells and oxygen separation membranes. Doping PrNi1-xCoxO3-δ by Sm results in suppression of the fast channel of oxygen diffusion along extended defects due to Sm segregation in their vicinity. For nanocomposites moderate doping by Sm enhances fast oxygen diffusion in fluorite phase domains and along perovskite-fluorite interface due to a higher disordering caused by incorporation of both Pr and Sm cations into Y-doped ceria.

Doped La 2 − x R x Mo 2 − y W y O 9 (R = Bi, Gd, Pr, Sm, Nd; x = 0–0.5, y = 0.5–1) were synthesized via polymerized precursors method or high power mechanical milling (MM). The study of doped LAMOX genesis and structural properties using thermal analysis, XRD, TEM has revealed that for all cations substituting La-position, the pure cubic β-phase is formed from polymerized precursors after calcination at 700 °C. W-doped LAMOX have been obtained via low temperature calcination of MM products. Due to a high dispersion of powders, high density pellets of doped LAMOX ceramics have been already obtained after sintering at 950 °C. Their electrical conductivity measured by impedance spectroscopy varies in the range of 2.3–5.6 · 10 − 3 S/cm at 630 °C depending on the doping cation nature. The self-diffusion coefficient ( D O ) values calculated from corresponding conductivities is in the range of 6–14 · 10 − 9 cm 2 /s at 630 °C agreeing well with those from the data of C 18 O 2 SSITKA for oxygen isotope exchange with powders of LAMOX.

For La2Zr2O7/LaAlO3 composite prepared by aging (100 °C/10 h) of the mixture of precipitated precursors of La-Zr-O and La-Al-O, evolution of its structural features after sintering in air in the range of 100–1300 °C was investigated by applying XRD, HRTEM, FTIR, Raman and UV–Vis spectroscopies, 27Al MAS NMR and 139La NMR. The initial composite forms a highly dispersed and disordered structure retaining considerable concentrations of residual anions (anions from the initial salts, water molecules and hydrogen bound hydroxyls) due to basic properties of La cations. Stepwise removal of these anions by calcinations results in the crystallization of La2(Al)O2CO3 at 500 °C with complete disordering of the system after heating at 700 °C. These transitions are accompanied by appearance of AlO4 polyhedra. The La-Zr-O- containing phase appeared for the first time at 900 °C as fluorite-like ZrO2 stabilized by La (Al) cations, and LaAlO3 (P2) phase is also observed along with admixtures of La2O3 and La10Al4O21. At 1100 °C fluorite-like ZrO2 converts into the La2Zr2O7 (P1) phase, and in the range of 1100–1300 °C mixed P1 and P2 oxides are the main phases. For P1 phase, structure becomes more ordered at higher sintering temperatures, while for P2 phase in composite the nanodomain structure is still observed in comparison with individual mixed oxide at 1300 °C. The molecular –scale features of domain boundaries in nanostructured La-Zr-O/La-Al-O composite as well as applied inexpensive method of its fabrication provide required bases for a broad practical application of this material for Thermal barrier coatings (TBCs).

International audience; Oxygen migration is increasingly acknowledged as playing an important role in the ionic transport in mixed conductors and influencing the electrode electrochemical performance. The aim of this work was to establish correlations between the structural and electrical properties of undoped (Ln2NiO4 + δ, Ln = La, Pr) and doped (La1.7M0.3NiO4 + δ, M = Ca, Sr, Ba, La0.85Pr0.85Ca0.3NiO4 + δ, Pr1.7Ca0.3NiO4 + δ) layered nickelates and the oxygen diffusion in these materials to determine what influences their electrochemical response. A new technique for temperature programmed isotope exchange of oxides with C18O2 in a flow reactor was applied to investigate oxygen mobility and surface reactivity in the polycrystalline powder samples which provided the means to experimentally demonstrate the appearance of two channels of oxygen migration in the doped materials via cooperative mechanism and via near-dopant position. The electrochemical performance of the electrodes based on the developed materials was found to exhibit a strong dependence on their oxygen transport characteristics.

Cobalt-doped praseodimium nickelates PrNi 1 − x Co x O 3 − δ and Y/(Pr, Y)-doped ceria oxides were synthesized via Pechini route. Nanocomposites were prepared via ultrasonic dispersion of the mixture of perovskite and fluorite nanopowders in isopropanol with addition of polyvinyl butyral followed by drying, pressing and sintering at 1000–1100 °C. The oxygen mobility and reactivity of perovskites, fluorites and powdered composites obtained by crushing and milling of pellets were estimated by oxygen isotope heteroexchange with 18 O 2 and C 18 O 2 using both closed and flow (SSITKA) reactors in the temperature-programmed (TPIE) mode. Co-existence of two routes of oxygen bulk diffusion—the fast one and the slow one in perovskites and composites was revealed. In perovskites, the fast oxygen diffusion is a minor channel related to some defects in their structure. In composites, the fast oxygen diffusion is the main route being related to both phases disordered due to cation redistribution between them, first of all, to fluorite-like domains of Pr,Y-doped ceria and perovskite/fluorite interfaces.

Ce3+-doped borate crystal fibers of Li6Gd(BO 3)3 (LGBO) and Li6Y(BO3)3 (LYBO) compositions are grown by the micro-pulling down (μ-PD) method for potential application in developing new neutron detectors. The ternary equilibrium diagram of Li2O-Gd2O3-B 2O3 is drawn and the preparations of homogeneous mixed LGBO and LYBO powders and growth conditions for single crystal fibers are discussed. Absorption, excitation and X-ray luminescence spectra are investigated. Absolute light yield derived from energy spectra and kinetic decay curves measured under α- and γ-scintillations of Ce 3+-doped LGBO and LYBO single crystal fibers is provided. © 2012 Elsevier B.V. All rights reserved.

The present report represents an overview of the results of a combined experimental-computational study of electronic structure, thermoluminescence (TL) and afterglow properties of Ca2 Ge7 O16 :Dy3+ synthesized for the first time. Afterglow curves of Ca2 Ge7 O16 :Dy3+ at 575 nm showing persistent luminescence have been described in Becquerel law. The TL measurements reveal at least one TL band at 326 K and two luminescence bands at 475 and 535 nm. Persistent luminescence in Ca2 Ge7 O16 :Dy3+ originates from relatively shallow charge traps with high probability of charge carriers recapture. The model of energy processes, configurations of traps and luminescence centers has been proposed with the aid of ab initio calculations performed using the LCAO approximation and several hybrid functionals.

LnFe0.7Ni0.3O3−δ (Ln = La, Pr, Sm) perovskites synthesized via Pechini method have been studied as catalysts of methane dry reforming (MDR). Effects of pretreatment and type of Ln cation on the structural and redox properties of perovskites and their catalytic performance have been elucidated. The most active catalysts are obtained by keeping perovskites in the reaction feed at high temperatures due to the formation of Ni–Fe alloy particles released from the perovskite lattice and stabilized on its surface. PrFe0.7Ni0.3O3−δ was found to be the most active and stable catalyst due to the optimal composition of segregated Ni–Fe alloy particles and redox properties of oxide matrix.

Main features of structured catalysts performance in bio-fuels reforming into syngas at lab-scale and pilot-scale levels using specially designed reactors and kinetic installations allowing to broadly tune the operational parameters are presented. Effects of the nature of nanocomposite active component comprised of Ru + Ni nanoparticles on bulk/alumina-supported perovskite or Mn–Cr–O spinel, type of substrate (Ni–Al alloy and SiC(Al 2 O 3 )/Al–Si–O foam substrates, Fechraloy microchannel plates or gauzes protected by thin corundum layer), type of fuel (natural gas, ethanol, acetone, ethyl acetate glycerol), feed composition and temperature on yield of syngas/byproducts and performance stability are considered. The best performance in real feeds with syngas yield approaching equilibrium at short contact times without any heat/mass transfer effects along with a high thermochemical stability were demonstrated for catalyst on heat-conducting microchannel substrate. Oxygen addition to the feed in optimized amounts allows to suppress coking and stabilize performance even for the case of such reactive fuel as glycerol only slightly affecting syngas yield.

Molecular dynamic simulations of pure dimethyl sulfoxide, DMSO (216 molecules) and its “infinitely diluted solutions” of Na + and Cl − (1 ion and 215 solvent molecules) have been performed at 298.15 K in NVT ensemble by using a force field model introduced by Liu, Muller-Plathe and van Gunsteren (J. Amer. Chem. Soc., 117 (1995) 4363) and a potential of shifted force. The structure of the solutions is discussed in terms of radial distribution functions, orientation of the DMSO molecules, and their geometrical arrangement in the first solvation shells. Dynamics of the first and second solvation shells are studied in terms of mean square displacement of the centre-of-mass of DMSO molecules, and the reorientational autocorrelation functions of dipole moment and SO bond vectors. It is found that the first solvation shell of Na + consists of 6 DMSO molecules located at the vertices of a distorted octahedron and oriented by their polar SO bonds towards the cation with a preferable angle of 156° between SO and Na-S vectors. Translational and reorientational mobilities of the DMSO molecule within the first solvation shell of the cation are significantly lower than in the bulk solvent. The first solvation shell of Cl − does not indicate a regular polygonal arrangement. It consists of 10 DMSO molecules oriented by their methyl groups and sulphur atoms towards the anion with a preferable angle of about 90° between the bisector of ∠CSC and the vector pointing from Cl − to the median point between two methyl groups. The dynamic behaviour of the solvent molecules in the first solvation shell of the anion and in the bulk solvent are found to be similar.

For two series of catalysts based on praseodymium ferrite, their structural and redox properties as well as performance in ethanol steam reforming have been studied. The first series was PrFe

LnFeNi(Ru)O3 perovskites synthesized via a modified Pechini method have been studied as catalyst precursors in CO2 reforming of methane. The structural and redox properties along with catalytic performance were found to depend upon Ln nature and Ru content in the perovskite. Active and stable catalysts have been formed from perovskite precursors in reaction media at high temperatures due to Fe–Ni–(Ru) alloy particles segregation from the perovskite lattice and their stabilization on the oxide surface. Coking stability of these catalysts in dry reforming of real natural gas containing admixtures of higher hydrocarbons is explained by combined effects of Ni dilution by Ru in alloy nanoparticles and high mobility and reactivity of surface/lattice oxygen in the disordered Ln ferrite support.