ABSTRACT
ABSTRACT
ABSTRACT Low loading (10% wt) Pt catalysts supported on short-length carbon nanotubes have superior performances and esp. significantly reduced deactivation in the presence of 50 ppm of CO with respect to com. higher loading (20% wt)... more
ABSTRACT Low loading (10% wt) Pt catalysts supported on short-length carbon nanotubes have superior performances and esp. significantly reduced deactivation in the presence of 50 ppm of CO with respect to com. higher loading (20% wt) bimetallic (Pt-Ru) catalysts, or of longer-length CNT. The effect is attributed to the defective nature of these short-length MWCNT used as support for the Pt metal particles. [on SciFinder(R)]
Research Interests:
ABSTRACT
Two approaches to connect single silicon nanocrystals (Si-nc) with multiwalled carbon nanotubes (MWCNTs) are studied. The first consists of direct growth of the MWCNTs in tapered element oscillating microbalance by chemical vapour... more
Two approaches to connect single silicon nanocrystals (Si-nc) with multiwalled carbon nanotubes (MWCNTs) are studied. The first consists of direct growth of the MWCNTs in tapered element oscillating microbalance by chemical vapour deposition process on coated Si-nc with iron based catalyst. The second procedure, at room temperature connects and introduces dispersed Si-nc (2- 5 nm) in colloidal suspension of spin on glass by capillary forces.
Research Interests:
... Gauthier Wine´*, Marc-Jacques Ledoux, and Cuong Pham-Huu Laboratoire des Materiaux, Surfaces et Procede´s pour la Catalyse (LMSPC), Part of the ELCASS (European Laboratory of Catalysis and Surface ... [18] M. Spagnol, L. Gilbert, H.... more
... Gauthier Wine´*, Marc-Jacques Ledoux, and Cuong Pham-Huu Laboratoire des Materiaux, Surfaces et Procede´s pour la Catalyse (LMSPC), Part of the ELCASS (European Laboratory of Catalysis and Surface ... [18] M. Spagnol, L. Gilbert, H. Guillot and PJ Tirel, US Patent No. ...
Research Interests:
Research Interests:
Research Interests:
The synthesis of a hierarchical support, constituted of a network of SiC nanofibers deposited on a SiC foam host resulting in a ceramic material with a controlled macroscopic shape and associated high specific surface area superior to 50... more
The synthesis of a hierarchical support, constituted of a network of SiC nanofibers deposited on a SiC foam host resulting in a ceramic material with a controlled macroscopic shape and associated high specific surface area superior to 50 m 2 g −1 , has been reported for the first time. ...
Research Interests:
The growth of multiwalled carbon nanotubes (MWCNTs) produced by a catalytic chemical vapor deposition (CCVD) process has been monitored using a tapered element oscillating microbalance (TEOM) probe. This technique displays a high... more
The growth of multiwalled carbon nanotubes (MWCNTs) produced by a catalytic chemical vapor deposition (CCVD) process has been monitored using a tapered element oscillating microbalance (TEOM) probe. This technique displays a high sensitivity (<1 microg). Growths in the TEOM microreactor are investigated with catalytic particles (Fe, Ni) dispersed on different supports. First, high surface area FeAl2O3 or Fe (Ni) exchanged on zeolite powders is used. Second, growths are performed on array of nickel dots or FeSi-nc particles dispersed on large holes patterned on Si(100) substrates. An accurate monitoring of the early stages of growth permits a precise evaluation of the growth rates and shows substantial differences between these samples which greatly differ by the surface area. On catalysts dispersed on Si(100) the mass uptake is linear throughout the process. On high surface area catalysts, however, a saturation of the mass uptake is indifferently observed. This saturation is explained either by diffusion limitation by the growing MWCNTs or by internal diffusion through the pores or external diffusion through the grains of the catalyst. The kinetic dependence with partial pressure of the incoming C2H6:H2 gas mixture is then explored on the FeAl2O3 catalyst. A linear dependence of the MWCNT growth an (P(C2H6)/P(H2))(1/2) is found. A simple model is then developed that accounts for this dependence only if an associative and competitive adsorption of ethane is the rate determining step of the overall process. These results thus bring insight to improve and control the CCVD growth kinetics of MWCNTs.
Research Interests:
Research Interests:
Research Interests: Chemical Engineering, Materials Science, Catalysis, Scanning Electron Microscopy, Transmission Electron Microscopy, and 13 moreHeterogeneous Catalysis, Catalyst, Maleic Anhydride, Specific surface area, High Resolution, Activated Charcoal, Surface Area, X ray diffraction, Room Temperature, Thermal Treatment, Surface Properties, Shape Memory, and Oxidation
Research Interests:
... therefore were transferred into the adsorption cell via a glovebox maintained under dry N 2 ... over MoO 3 and MoO 3 -Carbon-Modified Catalyst at Atmospheric Pressure (Reaction Conditions ... the product distribution led to the... more
... therefore were transferred into the adsorption cell via a glovebox maintained under dry N 2 ... over MoO 3 and MoO 3 -Carbon-Modified Catalyst at Atmospheric Pressure (Reaction Conditions ... the product distribution led to the conclusion that the isomerization reaction over MoO 3 ...
Research Interests:
Molybdenum oxycarbide formed from oxidized Mo 2 C or reduced MoO 3 is an active and very selective catalyst for the isomerization of n-heptane compared to supported Pt. Deactivation experiments performed on the catalysts with different... more
Molybdenum oxycarbide formed from oxidized Mo 2 C or reduced MoO 3 is an active and very selective catalyst for the isomerization of n-heptane compared to supported Pt. Deactivation experiments performed on the catalysts with different concentrations of organosulfur compounds show ...
Research Interests:
Page 1. Ind. Eng. Chem. Res. 1995,34, 1107-1113 1107 Reactions of n-Heptane and Methylcyclopentane over an Oxygen-Modified Molybdenum Carbide Catalyst. Study of Coke Formation, Catalyst Deactivation, and Regeneration ...
Research Interests:
Research Interests:
The arrays of vertically aligned carbon nano-filaments (VACNF) were synthesized by catalytic chemical vapor deposition on TiOx substrates, obtained via oxidative treatment of polycrystalline Ti and Ti thin films on Si(100). VACNF were... more
The arrays of vertically aligned carbon nano-filaments (VACNF) were synthesized by catalytic chemical vapor deposition on TiOx substrates, obtained via oxidative treatment of polycrystalline Ti and Ti thin films on Si(100). VACNF were studied using scanning and transmission electron microscopies. The Pt deposition on VACNF was utilized to prepare a set of model catalysts, which were investigated in two fuel cell related reactions: the oxygen reduction (ORR) and the hydrogen oxidation (HOR) reactions. The experimental data were compared with the results of mathematical modeling performed for a fast (quasi)reversible and a slow irreversible electrochemical reaction. The approach made it possible to study electrochemical reactions (HOR, ORR) on nano-materials under well defined mass transport conditions. The influence of the catalytic layer thickness and the Pt coverage on the penetration depth of the reactive species inside the layer and consequently on the performance and on the Pt effectiveness factor were analyzed.
Research Interests: Engineering, Carbon, Modeling, Nanoparticle, Scanning Electron Microscopy, and 21 moreMorphology, Transmission Electron Microscopy, Electrocatalysis, Fuel Cell, Chemical Vapor Deposition, Thin Film, Physical sciences, Nanostructure, Mass Transport, CHEMICAL SCIENCES, Mathematical Model, Surface Structure, Single Crystal, Titanium Oxides, Three Dimensional, Oxidation, Oxygen Reduction Reaction, Oxygen Reduction, Penetration Depth, Thiele Modulus, and Experimental Data(Morphology, Transmission Electron Microscopy, Electrocatalysis, Fuel Cell, Chemical Vapor Deposition, Thin Film, Physical sciences, Nanostructure, Mass Transport, CHEMICAL SCIENCES, Mathematical Model, Surface Structure, Single Crystal, Titanium Oxides, Three Dimensional, Oxidation, Oxygen Reduction Reaction, Oxygen Reduction, Penetration Depth, Thiele Modulus, and Experimental Data)
(Morphology, Transmission Electron Microscopy, Electrocatalysis, Fuel Cell, Chemical Vapor Deposition, Thin Film, Physical sciences, Nanostructure, Mass Transport, CHEMICAL SCIENCES, Mathematical Model, Surface Structure, Single Crystal, Titanium Oxides, Three Dimensional, Oxidation, Oxygen Reduction Reaction, Oxygen Reduction, Penetration Depth, Thiele Modulus, and Experimental Data)
Preparation and characterisation of a highly active and stable beta zeolite supported on a pre-shaped silicon carbide catalyst for the benzoylation reaction in liquid phase.
Research Interests:
Research Interests:
Beta zeolite supported on silicon carbide for Friedel–Crafts fixed-bed reactionsElectronic supplementary information (ESI) available: Temperature-pressure oxidation spectra and mechanism of phenyl benzoate formation without the participation of phenol. See http://www.rsc.org/suppdata/cc/b2/b209858j/more
Research Interests:
Controlled reduction of MoO3 can produce different phases of catalytic interest. One of these phases has been considered as being an oxycarbide of molybdenum. Various techniques mainly TEM but also XRD and others have been extensively... more
Controlled reduction of MoO3 can produce different phases of catalytic interest. One of these phases has been considered as being an oxycarbide of molybdenum. Various techniques mainly TEM but also XRD and others have been extensively used to understand the mechanism of formation and the structure of this oxycarbide. Its structure is reminiscent of the MoO3 structure as shown by
Research Interests:
Research Interests:
ABSTRACT
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
ABSTRACT
Research Interests:
Microwave heating can be efficiently used to carry out the liquid-phase acylation of anisole by acetic anhydride or benzoyle chloride: at 80° C the rate of the reaction increases dramatically compared to a traditional heating. In... more
Microwave heating can be efficiently used to carry out the liquid-phase acylation of anisole by acetic anhydride or benzoyle chloride: at 80° C the rate of the reaction increases dramatically compared to a traditional heating. In addition, according to the results a ...
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Mesoporous multi-walled carbon nanotubes (MWNTs) with an average inner diameter of about 50 nm were successfully used as a one-dimensional catalyst support either in gas-phase, ie selective oxidation of H 2 S into elemental sulfur in a... more
Mesoporous multi-walled carbon nanotubes (MWNTs) with an average inner diameter of about 50 nm were successfully used as a one-dimensional catalyst support either in gas-phase, ie selective oxidation of H 2 S into elemental sulfur in a thrickle-bed configuration, or in ...
Research Interests:
Research Interests:
... of 38 Accepted Manuscript Catalytic growth of silicon carbide composite with nanoscopic properties and enhanced oxidative resistance as catalyst support Adrien Deneuvea*, Ileana Floreab, Ovidiu Ersenb, Patrick Nguyenc, Charlotte... more
... of 38 Accepted Manuscript Catalytic growth of silicon carbide composite with nanoscopic properties and enhanced oxidative resistance as catalyst support Adrien Deneuvea*, Ileana Floreab, Ovidiu Ersenb, Patrick Nguyenc, Charlotte Phamc, Dominique B gina, David Edouarda ...
Research Interests:
Research Interests:
ABSTRACT The invention relates to: a method of preparing a solid material based on tangled nanotubes and/or nanofibres, comprising a step consisting in growing carbon nanofibres and/or nanotubes with restraint in a contained reactor; and... more
ABSTRACT The invention relates to: a method of preparing a solid material based on tangled nanotubes and/or nanofibres, comprising a step consisting in growing carbon nanofibres and/or nanotubes with restraint in a contained reactor; and the materials thus obtained. The invention also relates to the different uses of said materials.
Research Interests:
Assemblies of nanoparticles are studied in many research fields from physics to medicine. However, as it is often difficult to produce mono-dispersed particles, investigating the key parameters enhancing their efficiency is blurred by... more
Assemblies of nanoparticles are studied in many research fields from physics to medicine. However, as it is often difficult to produce mono-dispersed particles, investigating the key parameters enhancing their efficiency is blurred by wide size distributions. Indeed, near-field methods analyse a part of the sample that might not be representative of the full size distribution and macroscopic methods give average information including all particle sizes. Here, we introduce temperature differential ferromagnetic nuclear resonance spectra that allow sampling the crystallographic structure, the chemical composition and the chemical order of non-interacting ferromagnetic nanoparticles for specific size ranges within their size distribution. The method is applied to cobalt nanoparticles for catalysis and allows extracting the size effect from the crystallographic structure effect on their catalytic activity. It also allows sampling of the chemical composition and chemical order within the size distribution of alloyed nanoparticles and can thus be useful in many research fields.