References of "Heinrichs, Benoît"
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See detailDécomposition photocatalytique de polluants et de micro-organismes dans l'eau
Heinrichs, Benoît ULg; Pirard, Jean-Paul ULg; Lambert, Stéphanie ULg et al

E-print/Working paper (2008)

Dans le cadre de la réutilisation des eaux usées et de l’accès limité à l’eau potable dans certaines régions du globe, de nouvelles techniques de désinfection nécessitant de faibles consommations ... [more ▼]

Dans le cadre de la réutilisation des eaux usées et de l’accès limité à l’eau potable dans certaines régions du globe, de nouvelles techniques de désinfection nécessitant de faibles consommations d’énergie sont étudiées. Cette eau n’est pas toujours potable et contient des polluants qui induisent des mutations génétiques pouvant conduire au développement de cancers ou encore des micro-organismes pathogènes causant des maladies graves. Depuis la découverte des propriétés de photodégradation oxydante du dioxyde de titane (TiO2), la photocatalyse hétérogène est utilisée pour l’élimination des polluants environnementaux et des micro-organismes. [less ▲]

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See detailIron(III) species dispersed in porous silica through sol-gel chemistry
Heinrichs, Benoît ULg; Rebbouh, Leila; Geus, John W et al

in Journal of Non-Crystalline Solids (2008), 354(2-9), 665-672

Fe/SiO2 catalysts have been prepared by two different sol-gel methods, cogelation and dissolution. The cogelation and dissolution preparative methods lead to xerogels with fundamentally different pore ... [more ▼]

Fe/SiO2 catalysts have been prepared by two different sol-gel methods, cogelation and dissolution. The cogelation and dissolution preparative methods lead to xerogels with fundamentally different pore width distributions. The nature of the iron species obtained has been examined in detail by UN-visible and Mossbauer spectroscopy, and magnetic, transmission electron microscopy, and X-ray diffraction studies. There is no evidence for the presence of any ordered iron(III) oxides in the samples but all three contain two types of iron species, specifically paramagnetic high-spin iron(III) ions isolated in silica and iron(III) containing nanoparticles with a broad width distribution centered on 1.5 nm, nanoparticles that contain antiferromagnetically coupled clusters of a few ligated bridged iron(III) ions. (C) 2007 Elsevier B.V. All rights reserved. [less ▲]

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See detailOptimization of experimental procedure and statistical data treatment for kinetics of ethylene hydrogenation on a copper-magnesia catalyst
Pirard, Sophie ULg; Heinrichs, Benoît ULg; Heyen, Georges ULg et al

in Chemical Engineering Journal (2008), 138(1-3), 367-378

This study is an example of practical application of kinetic data treatment for simultaneous model discrimination and parameter estimation. The study is applied to the hydrogenation of ethylene on a ... [more ▼]

This study is an example of practical application of kinetic data treatment for simultaneous model discrimination and parameter estimation. The study is applied to the hydrogenation of ethylene on a copper-magnesia catalyst and brings a deepened analysis about the experimental strategy by comparing several alternative strategies using a priori and sequential experimental designs. The best model corresponds to a Langmuir-Hinshelwood mechanism with non-competing adsorption of hydrogen and ethylene and where the rate-determining step is either the addition of molecularly adsorbed hydrogen or the addition of the second atom of hydrogen adsorbed dissociatively. Furthermore, the important question of knowing in practice how many designs and how many measurements per design are actually necessary to determine accurate kinetic and physico-chemical parameters, is addressed. A data correction procedure is also presented that takes catalyst deactivation into account. (C) 2007 Elsevier B.V. All rights reserved. [less ▲]

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See detailCarbon xerogels as catalyst supports
Job, Nathalie ULg; Léonard, Angélique ULg; Lambert, Stéphanie ULg et al

Poster (2007, August)

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See detailIntroduction to sol-gel process
Heinrichs, Benoît ULg

Scientific conference (2007, March 14)

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See detailCarbon nanotubes synthesis by the ethylene chemical catalytic vapour deposition (CCVD) process on Fe, Co, and Fe-Co/Al2O3 sol-gel catalysts
Tran, Kim Yên; Heinrichs, Benoît ULg; Colomer, Jean-François et al

in Applied Catalysis A : General (2007), 318

The production of carbon nanotubes by the chemical catalytic vapour deposition, CCVD, process was examined over iron, cobalt, and a mixture of iron and cobalt supported on alumina catalysts synthesized by ... [more ▼]

The production of carbon nanotubes by the chemical catalytic vapour deposition, CCVD, process was examined over iron, cobalt, and a mixture of iron and cobalt supported on alumina catalysts synthesized by a one step sol-gel process. The catalysts were synthesized from several metal precursors, iron nitrate, cobalt and iron acetylacetonate, and cobalt acetate. Ethylene was used as the carbon source. The Co/Al2O3 catalysts showed better activity and selectivity in carbon nanotubes synthesis than Fe/Al2O3 and Fe-Co/Al2O3 catalysts. The carbon deposit was found by TEM analysis to be rich in carbon nanotubes in the case of Co/Al2O3 but to be very poor in the case of the Fe-Co/Al2O3 catalysts. The catalysts were characterized by TEM, XRD, and nitrogen adsorption. It was shown that iron and cobalt are in oxide form. Metal-support interactions and metal oxide particle size are influenced by the nature of the precursor and this nature is an important factor for the activity and selectivity of the catalysts. Moreover, a correlation has been found between the metal oxide particle sizes, the diameter of the carbon nanotubes, and the catalytic activity. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailPhotodegradation of bacteria with TiO2 produced by sol-gel method
Tasseroul, Ludivine ULg; Pàez Martinez, Carlos ULg; Braconnier, Benoît et al

Poster (2007)

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See detailAg/SiO2, Cu/SiO2 and Pd/SiO2 cogelled xerogel catalysts for benzene combustion: Relationships between operating synthesis variables and catalytic activity
Lambert, Stéphanie ULg; Cellier, Caroline; Gaigneaux, Eric M et al

in Catalysis Communications (2007), 8(8), 1244-1248

The aim of this work is to explore the applicability of the sol-gel method for the preparation of Ag/SiO2, Cu/SiO2 and Pd/SiO2 catalysts and to see whether such a method can yield silver, copper and ... [more ▼]

The aim of this work is to explore the applicability of the sol-gel method for the preparation of Ag/SiO2, Cu/SiO2 and Pd/SiO2 catalysts and to see whether such a method can yield silver, copper and palladium species stabilized by the carrier in the case of benzene oxidation. So Ag/SiO2, Cu/SiO2 and Pd/SiO2 xerogel catalysts were synthesized by cogelation of tetraethoxysilane (TEOS) and chelates of Ag, Cu and Pd with 3-(2-aminoethylamino)-propyltrimethoxysilane (EDAS). The resulting catalysts are composed of completely accessible metallic crystallites with a diameter of about 3 nm located inside silica particles. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailSol-gel synthesis of supported metals
Heinrichs, Benoît ULg; Lambert, Stéphanie ULg; Job, Nathalie ULg et al

in Regalbuto, John R. (Ed.) Catalyst Preparation : Science and Engineering (2007)

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See detailOn the structure-sensitivity of 2-butanol dehydrogenation over Cu/SiO2 cogelled xerogel catalysts
Lambert, Stéphanie ULg; Cellier, Caroline; Ferauche, Fabrice et al

in Catalysis Communications (2007), 8

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See detailSynthesis of highly dispersed Pd/SiO2 cogelled xerogel catalysts from various silylated ligands
Lambert, Stéphanie ULg; Tran, Kim Yên; Arrachart, Guilhem et al

Poster (2007)

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See detailCarbon xerogels as catalyst supports for PEM fuel cell cathode
Job, Nathalie ULg; Marie, Julien; Lambert, Stéphanie ULg et al

Conference (2007)

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See detailMethods for the preparation of bimetallic xerogel catalysts designed for chlorinated wastes processing
Lambert, Stéphanie ULg; Ferauche, Fabrice; Heinrichs, Benoît ULg et al

in Journal of Non-Crystalline Solids (2006), 352(26-27), 2751-2762

The aim of this work is to simplify and generalize the synthesis procedure of bimetallic supported catalysts by sol-gel process. For Pd-Ag/SiO2, co-gelled xerogels catalysts a number of synthesis ... [more ▼]

The aim of this work is to simplify and generalize the synthesis procedure of bimetallic supported catalysts by sol-gel process. For Pd-Ag/SiO2, co-gelled xerogels catalysts a number of synthesis procedures were compared: use of one or two specific alkoxides able to form a chelate with palladium and/or silver cations, reagent mixing in one or two steps, use of industrial grade chemicals instead of laboratory grade chemicals. The catalysts obtained are quite similar: same metal dispersion, same tailored morphology, same localization and accessibility of Pd-Ag alloy nanoparticles inside microporous silica, same activity and selectivity for hydrodechlorination of 1,2-dichloroethane into ethylene. For catalyst production at large scale the synthesis can be achieved in one step with 3-(2-aminoethyl)aminopropyltrimethoxysilane of industrial grade as chelating alkoxide, tetraethylorthosilicate (TEOS) of industrial grade and ethanol denatured with diethyl phthalate. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailMultigram scale synthesis and characterization of low-density silica xerogels
Alié, Christelle ULg; Tcherkassova, Natalia ULg; Ferauche, Fabrice et al

in Journal of Non-Crystalline Solids (2006), 352(26-27), 2763-2771

The synthesis of silica with preserved porosity and tailored morphology by sol-gel process can be achieved by hybrid organic-inorganic synthesis: a modified alkoxide, viz. 3-(2-aminoethylamino ... [more ▼]

The synthesis of silica with preserved porosity and tailored morphology by sol-gel process can be achieved by hybrid organic-inorganic synthesis: a modified alkoxide, viz. 3-(2-aminoethylamino)propyltrimethoxysilane (EDAS), is introduced during the base catalysed synthesis with TEOS as main silica precursor. Additives with methoxy groups induce a nucleation mechanism because of their higher reactivity compared to main reagents with ethoxy groups. The nucleation model presented in previous papers was refined by taking into account the porosity of the particles and calculating the number of additive molecules by nucleus for each value of the ratio of additive/main reagent. The extrapolation of the synthesis process to semi-industrial scale goes through the replacement of laboratory grade reagents by industrial grade reagents and the scaling up to the production of higher quantities. At each of these two steps, the morphology and porosity of the samples has been compared to those of laboratory grade samples. It was shown that the texture and particle size has quasi totally been preserved. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailA TEM study on the localization of metal particles in cogelled xerogel catalysts
Heinrichs, Benoît ULg; Geus, J. W.; Lambert, Stéphanie ULg et al

in Journal of Catalysis (2006), 241(1), 229-231

The localization of metal and alloy particles in monometallic Pd/SiO2 and bimetallic Pd-Ag/SiO2 sol-gel catalysts prepared by cogelation was examined by rotating transmission electron microscopy. The ... [more ▼]

The localization of metal and alloy particles in monometallic Pd/SiO2 and bimetallic Pd-Ag/SiO2 sol-gel catalysts prepared by cogelation was examined by rotating transmission electron microscopy. The analysis of the resulting micrograph series provides a direct proof that the 2-to 3-nm active metal nanoparticles in those catalysts are located inside microporous silica particles or aggregates. Such localization has long been suspected but with, up to now, no direct evidence. (c) 2006 Elsevier Inc. All rights reserved. [less ▲]

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See detailPd-Ag/SiO2 xerogel catalyst forming by impregnation on alumina foams
Alié, Christelle ULg; Ferauche, Fabrice; Léonard, Angélique ULg et al

in Chemical Engineering Journal (2006), 117(1), 13-22

A Pd-Ag/SiO2 xerogel catalyst prepared in one step by sol-gel process has been entrapped in cylindrical porous alumina foams of three different pore sizes in order to shape the catalyst under the ... [more ▼]

A Pd-Ag/SiO2 xerogel catalyst prepared in one step by sol-gel process has been entrapped in cylindrical porous alumina foams of three different pore sizes in order to shape the catalyst under the appropriate form with suitable mechanical resistance to be used in an industrial fixed bed reactor. After drying, calcination and reduction, the Pd-Ag/SiO2 xerogel catalyst pellets are immobilized inside the open porosity of the alumina foam. The localization of the xerogel catalyst in the alumina foams has been studied by X-ray tomography. The three-dimensional porous structure was reconstructed from the consecutive cross-sections obtained by this technique. This method shows that the Pd-Ag/SiO2 xerogel catalyst is uniformly dispersed inside the porosity of the alumina foams. Activity and selectivity of Pd-Ag/SiO2 xerogel catalyst reference or catalyst entrapped in alumina foams have been studied for selective hydrodechlorination of 1,2-dichloroethane into ethylene. The specific reaction rate obtained with catalyst entrapped in alumina foams is smaller than the one obtained from corresponding catalyst powders. The catalytic activity decrease observed for Pd-Ag/SiO2 xerogel catalyst entrapped in porous alumina foams most probably arises from diffusional limitations inside the porous texture of the alumina foams. (c) 2005 Elsevier B.V. All rights reserved. [less ▲]

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See detailThe nonlinear optical, magnetic, and Mossbauer spectral properties of some iron(III) doped silica xerogels
Rebbouh, L.; Rosso, Vanessa ULg; Renotte, Yvon ULg et al

in Journal of Materials Science (2006), 41(10), 2839-2849

Iron(III) species dispersed in silica have been synthesized with a sol-gel process. The iron(III) was introduced as the acetylacetonate complex into a solution of tetraethoxysilane to yield, after ... [more ▼]

Iron(III) species dispersed in silica have been synthesized with a sol-gel process. The iron(III) was introduced as the acetylacetonate complex into a solution of tetraethoxysilane to yield, after evaporative drying, pellets or monoliths. Two gels were dried very slowly over a period of five months in order to prepare a defect free monolith useful for nonlinear optical studies. Z-scan experimental studies on the resulting, transparent, monolithic, doped solid revealed an optical Kerr effect, a third order nonlinear optical phenomenon showing a linear dependence of the refractive index on the irradiance with a nonlinear refractive index, n(2), of -1.95 x 10(-11) cm(2)/W. Magnetic susceptibility studies between 4.2 and 295 K revealed paramagnetic behavior with a Curie constant of 4.433 (emu/mol)K and a Weiss temperature of -7.1 K. Magnetization studies at 5 K and at applied fields of up to 4 T and Mossbauer spectral studies between 4.2 and 295 K revealed a 50:50 mixture of paramagnetic species and nanoparticles with an average particle radius of 1.3 +/- 0.2 nm. A blocking temperature of 70 K and a magnetic anisotropy energy of 2.4 x 10(5) J/m(3) stop are derived from the Mossbauer spectra. (c) 2006 Springer Science + Business Media, Inc. [less ▲]

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