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Sainte-Foy-lès-Lyon, France

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. Source

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. Source

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). Source

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). Source

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. Source

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