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Helgadottir I.S.,CNRS Laboratory of Chemistry, Catalysis, Polymers and Process | Helgadottir I.S.,CEA Grenoble | Arquilliere P.P.,CNRS Laboratory of Chemistry, Catalysis, Polymers and Process | Arquilliere P.P.,CEA Grenoble | And 6 more authors.
Microelectronic Engineering | Year: 2013

To meet the constant challenges of miniaturization in the microelectronics industry, new innovative pathways must be explored to produce nano-objects. Ionic liquids (ILs) can be used to generate and stabilize metallic nanoparticles (MNPs) by several physical and chemical routes. Here, the simultaneous decomposition of Ru and Cu organometallic precursors in IL is shown to yield core-shell Ru@CuNPs with smaller diameters and narrower size distributions than the corresponding monometallic NPs, in a broad range of Ru:Cu compositions. They are probably formed by rapid nucleation of Ru cores followed by decomposition of the Cu precursor on their surface. This effect forces the formation of a bimetallic structure that does not form with the use of purely physical processes such as PVD. These Cu, Ru, and Ru@CuNPs could be used for the formation of seed and barrier layers for the metallization of advanced interconnect structures. © 2012 Elsevier B.V. All rights reserved.

Kuznetsov B.N.,Siberian Federal University | Kuznetsova S.A.,Siberian Federal University | Levdansky V.A.,Siberian Federal University | Levdansky A.V.,RAS Institute of Chemistry and Chemical Technology | And 5 more authors.
Wood Science and Technology | Year: 2015

The methods of obtaining cellulose and cellulose sulfates from birch wood based on the use of one-step catalytic delignification of wood by hydrogen peroxide in acetic acid–water medium were studied. The conditions of birch wood oxidative delignification by acetic acid/hydrogen peroxide mixtures in the presence of sulfuric acid catalyst were optimized in order to obtain an acceptable yield of cellulose product with low content of residual lignin. Cellulose extracted from birch wood by green method was used for preparation of cellulose sulfates in dioxane solution. The homogeneous sulfation of obtained cellulose by chlorosulfonic acid in dioxane allows to reduce the fragmentation of polymer and to synthesize cellulose sulfates with a finer and more homogeneous structure as compared to cellulose sulfates prepared by heterogeneous sulfation in harmful pyridine. Obtained samples of cellulose and cellulose sulfates were characterized by XRD, SEM, AFM, NMR, FTIR, Raman, XPS and chemical methods. © 2015, Springer-Verlag Berlin Heidelberg.

Vasil'Eva N.Yu.,Siberian Federal University | Levdansky A.V.,RAS Institute of Chemistry and Chemical Technology | Kuznetsov B.N.,Siberian Federal University | Skvortsova G.P.,RAS Institute of Chemistry and Chemical Technology | And 3 more authors.
Russian Journal of Bioorganic Chemistry | Year: 2015

The sulfation of arabinogalactan (AG) by sulfamic acid in the presence of urea in dioxane has been studied. The degree of AG sulfation increases as the sulfation temperature increases from 70 to 95°C. As indicated by 13C NMR spectroscopy, the sulfate groups in sulfated AG are in the C2 and C4 positions of the main galactan chain and the C6 position of the terminal galactose units of the main and the side chains of AG. The sulfation of AG by the complex sulfamic acid-urea in dioxane medium makes it possible to increase the ecological safety and the efficiency of the process compared with the known methods of sulfation. © 2015 Pleiades Publishing, Ltd.

Kuznetsov B.N.,Siberian Federal University | Sudakova I.G.,RAS Institute of Chemistry and Chemical Technology | Garyntseva N.V.,RAS Institute of Chemistry and Chemical Technology | Djakovitch L.,IRCELYON | Pinel C.,IRCELYON
Reaction Kinetics, Mechanisms and Catalysis | Year: 2013

The process of aspen-wood delignification in the medium "hydrogen peroxide-acetic acid-water-sulfuric acid catalysts" at mild conditions (temperature 70-100 °C, atmospheric pressure) is described by the first order equation. Rate constants vary from 0.25 × 10-4 (70 °C) to 2.5 × 10-4 s-1 (100 °C). The activation energy of aspen-wood delignification is near 91 kJ mol-1. The rather high value of activation energy points to the insignificant role of diffusion limitations at used conditions of aspen-wood delignification. The optimal process conditions for obtaining of the pure cellulose (residual lignin content less 1 wt%) with a yield near 45 wt% were selected. Obtained cellulose has the structure similar to the commercial microcrystalline cellulose. © 2013 Akadémiai Kiadó, Budapest, Hungary.

Lettat K.,French Institute of Petroleum | Lettat K.,French National Center for Scientific Research | Jolimaitre E.,French Institute of Petroleum | Tayakout M.,IRCELYON | Tondeur D.,French National Center for Scientific Research
AIChE Journal | Year: 2011

This work provides a new mass transfer model based on the Maxwell-Stefan theory, especially adapted to represent adsorbed phase multicomponent diffusion at high-adsorbent loading. In our model-contrarily to the well-known model developed by Krishna et al. (Chem Eng Sci. 1990;45:7:1779-1791; Gas Sep Purif. 1993;7:91-104; J Phys Chem B. 2005;109:6386-6396)-the hypothesis that the micropores are saturated does not imply a dependency between the adsorbed phase diffusion coefficients. Experimental liquid phase breakthrough curves of 2-methylpentane (2MP), 3-methylpentane (3MP), 2,3-dimethylbutane (23DMB), and 2,2-dimethylbutane (22DMB) were measured at 458 K in silicalite. The self-diffusion coefficients and Langmuir parameters of the different species were determined using binary exchange breakthrough curves. The Maxwell-Stefan diffusion coefficients obtained for the different isomers are in the order D3MP,nc+1 > D2MP,nc+1 > D23DMB,nc+1, and vary between 4 × 10-15 m2 s-1 for 3MP to 6 × 10-16 m2 s-1 for 23DMB. The 22DMB diffusion coefficient is so low that it could not be estimated (the quantity of 22DMB entering silicalite during the experiment is not significant). The model was then validated by comparing experimental breakthrough curves at different feed concentrations and simulations using the independently estimated parameters. Even though the diffusion coefficients of the different isomers vary by one order of magnitude, the agreement between simulated and experimental curves is very satisfactory, showing the good predictive power of our model. © 2010 American Institute of Chemical Engineers (AIChE).

Sadykov V.,Novosibirsk State University | Mezentseva N.,Novosibirsk State University | Simonov M.,Novosibirsk State University | Smal E.,Novosibirsk State University | And 13 more authors.
International Journal of Hydrogen Energy | Year: 2015

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(Al2O3)/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. © 2015 Hydrogen Energy Publications, LLC.

Girard V.,French Institute of Petroleum | Chiche D.,French Institute of Petroleum | Baudot A.,French Institute of Petroleum | Bazer-Bachi D.,French Institute of Petroleum | Geantet C.,IRCELyon
12AIChE - 2012 AIChE Spring Meeting and 8th Global Congress on Process Safety, Conference Proceedings | Year: 2012

Integrated Gasification Combined Cycles (IGCC) and the second generation biofuels processes, and Fischer-Tropsch based XTL processes, are attractive alternatives for future power production. To prevent the corrosion of the industrial units, especially the combustion turbine blade used in IGCC processes or, in the others processes, to avoid the Fischer-Tropsch catalysts poisoning, deep desulfurization of synthesis gas is achieved with metal oxides. The large amounts of solid wastes produced are one of the major disadvantages of the in-situ desulfurization of synthesis gas. The in-situ regeneration of the sulfided sorbent, back to the oxide, during the process could resolve this problem. A new insight on the phenomena involved during the oxidative regeneration of the sulfided solids is described. The methodology developed is based on the confrontation between a global theoretical approach based on thermochemical data and an experimental study. Classification of the behaviors observed during both sulfidation and oxidative regeneration of simple oxides, in particular ZnO, are evaluated. The mixed oxides were evaluated, selected thanks to the results of the first part and by the anticipation of potential synergetic effects. The synergetic effects are expected to avoid the formation of refractory sulfates and the resulting increase of temperature. The simple oxides based on the stability of their sulfide and sulfate phases are evaluated. This classification led to a selection of different simple oxides whose mixture could bring synergetic effect. This methodology led to an innovative material which composition allows a fast regeneration, at 150°C lower than ZnO regeneration temperature and without sulfates formation. This is an abstract of a paper presented at the 2012 AIChE Spring Meeting and 8th Global Congress on Process Safety (Houston, TX 4/1-5/2012).

Testa M.L.,CNR Institute of Nanostructured Materials | Corbel-Demailly L.,IRCELYON | La Parola V.,CNR Institute of Nanostructured Materials | Venezia A.M.,CNR Institute of Nanostructured Materials | Pinel C.,IRCELYON
Catalysis Today | Year: 2015

The effect of different supports, silica HMS and Ti doped silica HMS, on the catalytic performance of mono (Pd) and bimetallic (Pd-Au, Pd-Re) catalysts, containing 2 wt% of each metal, for the hydrogenation of levulinic acid in water was studied. The catalytic behavior of the materials was evaluated in terms of conversion of the starting levulinic acid and selectivity to γ-valerolactone. The surface and structural properties of the catalysts were investigated by means of X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) performed on fresh and spent materials. A synergic effect of Au and Ti on Pd sample was observed with the consequent formation of a PdTi alloy responsible of the good performance of the catalyst. © 2014 Elsevier B.V. All rights reserved.

Blanquet E.,Grenoble Institute of Technology | Nuta I.,Grenoble Institute of Technology | Brize V.,Grenoble Institute of Technology | Boichot R.,Grenoble Institute of Technology | And 3 more authors.
ECS Transactions | Year: 2010

The most commonly use for gaseous precursors in CVD (Chemical Vapor Deposition) and ALD (Atomic Layer Deposition) processes are organometallic molecules. These ones are generally thermally unstable at low temperatures (400-600 K) and require an understanding of its gas-phase chemical behavior. The thermal cracking of the gaseous precursor PDMAT used in the CVD/ALD TaN deposition processes has been studied by Mass Spectrometry. Ta[N(CH 3) 2] 5(g), Ta[N(CH 3) 2] 4(g), N(CH 3) 2(g) together with TaO[N(CH 3) 2] 4(g) have been found to be the main molecules observed in the vapor phase originated from the PDMAT vaporization. The thermodynamic data of the O-free molecules have been evaluated from literature and statistical calculations. Comparison between experiments and thermodynamic simulations performed at different temperatures and pressures, evidenced kinetic limitations in the decomposition processes: ligand rupture and ligand decomposition. Furthermore, the experimental gas-phase study confirms the presence of oxygen containing molecules in the PDMAT cracking gaseous phase which explains the presence of oxygen in the deposited ALD TaN films. Thermodynamic simulations were also used to evaluate the use of hydrogen addition to the process. ©The Electrochemical Society.

The fundamentals of photocatalysis are the absorption of UV-photons, the generation of photo-électrons and holes, the adsorption of the reactants, and the proportionality of the reaction rate to the mass of catalyst, the photon flux and the surface coverage of the reactants. TiO2 (anatase) remains the best photocatalyst for environmental applications. For water treatment, inorganic pollutants are oxidized to their highest harmless oxidation degree. The organic pollutants (chemicals, pesticides, dyes, colorants, explosives, solvents...) are totally mineralized into CO2 and H2O. Water potabilization is obtained by detoxification and disinfection (degradation of bacteria and virus). Air treatment can be performed either in confined atmospheres with the elimination of volatile organic compounds, odors, toxic gases, bacteria..., or outside by solar photocatalysis with the elimination of odors emitted by food industries.

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