References of "Heinrichs, Benoît"
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See detailDevelopment by the sol–gel process of highly dispersed Ni–Cu/SiO2 xerogel catalysts for selective 1,2-dichloroethane hydrodechlorination into ethylene
Pirard, Sophie ULg; Mahy, Julien ULg; Pirard, Jean-Paul ULg et al

in Microporous and Mesoporous Materials (in press)

Ni–Cu/SiO2 xerogel catalysts have been synthesized by cogelation of industrial tetraethoxysilane (Dynasil) and chelates of Ni and Cu with industrial 3-(2-aminoethylamino)propyltrimethoxysilane (Dynasylan ... [more ▼]

Ni–Cu/SiO2 xerogel catalysts have been synthesized by cogelation of industrial tetraethoxysilane (Dynasil) and chelates of Ni and Cu with industrial 3-(2-aminoethylamino)propyltrimethoxysilane (Dynasylan DAMO) in industrial ethanol denatured with diethyl phthalate. Despite the use of industrial grade reagents, highly dispersed bimetallic Ni–Cu/SiO2 xerogel catalysts were obtained. These samples are composed of completely accessible Ni–Cu alloy crystallites with sizes of 1.6–3.4 nm located inside silica particles exhibiting a monodisperse microporous distribution. It appears that the bimetallic complex acts as a nucleation agent in the formation of silica particles. The combination of results obtained from the calculation of the metal ratio in catalysts, H2 chemisorption and transmission electron microscopy allowed calculating the surface composition of the nickel–copper particles in Ni–Cu/SiO2 cogelled xerogel catalysts. Values obtained indicate a very pronounced surface enrichment with copper. While 1,2-dichloroethane hydrodechlorination over pure nickel mainly produces ethane, increasing copper content in bimetallic catalysts results in an increase in ethylene selectivity. The specific consumption rate of 1,2-dichloroethane decreases when copper loading increases. The turnover frequency, that is, the number of catalytic cycle per active site (nickel atom and its surrounding copper atoms) and per second, seems to be independent of surface composition of alloy particles. [less ▲]

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See detailHighly dispersed iron xerogel catalysts for p-nitrophenol degradation by photo-Fenton effects
Mahy, Julien ULg; Tasseroul, Ludivine ULg; Zubiaur, Anthony ULg et al

in Microporous and Mesoporous Materials (2014), 197

Several iron xerogel catalysts were synthesized by hydrolysis and condensation of tetraethoxysilane (TEOS) and 3-(2-aminoethylamino)propyltrimethoxysilane (EDAS) which is able to form a chelate with iron ... [more ▼]

Several iron xerogel catalysts were synthesized by hydrolysis and condensation of tetraethoxysilane (TEOS) and 3-(2-aminoethylamino)propyltrimethoxysilane (EDAS) which is able to form a chelate with iron ions. The EDAS/TEOS ratio strongly influences the texture of xerogel catalysts. The specific surface area and the micro- and mesoporous volume increase with this ratio. It seems that EDAS plays a nucleating agent role for silica particles and allows to anchor Fe-based moieties inside the silica network. Iron oxide nanoparticles of diameter 1-1.5 nm and Fe3+ ions result, encapsulated in silica particles with sizes of about 10-30 nm in diameter. The iron species was determined by Mössbauer spectroscopy and magnetometry measurements and only Fe3+ species were observed in xerogel catalysts. The Fenton and photo-Fenton effect of these catalysts were evaluated on the degradation of p-nitrophenol in aqueous media under different conditions. Results show that in the presence of H2O2, iron xerogel catalysts present a photo-Fenton effect, reaching 99 % of degradation after 24 h. [less ▲]

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See detailHow to correctly determine the kinetics of a photocatalytic degradation reaction?
Pirard, Sophie ULg; Malengreaux, Charline ULg; Toye, Dominique ULg et al

in Chemical Engineering Journal (2014), 249

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See detailModification of Conductivity, Superhydrophilicity and Photocatalytic Activity of TiO2 Thin Films Through Carbon Nanotubes Doping
Léonard, Géraldine ULg; Remy, Simon; Malengreaux, Charline ULg et al

Poster (2014, July 15)

In this work, a superhydrophilic and photocatalytic material allowing to reduce the accumulation of electrostatic charges is developed. The superhydrophilicity and photocatalytic activity of TiO2 films ... [more ▼]

In this work, a superhydrophilic and photocatalytic material allowing to reduce the accumulation of electrostatic charges is developed. The superhydrophilicity and photocatalytic activity of TiO2 films provide the “easy-to-clean” property. Indeed, superhydrophilicity induces a very low contact angle between TiO2 and water leading to the formation of a water film at the surface of the material. The photocatalytic activity, responsible for the pollutant decomposition, is explained by the excitation of the semiconductor under UV light leading to the formation of electron-hole pairs. The electrical conductivity of semiconductor TiO2 is very low leading to the accumulation of electrostatic charges and so the surface becomes a dust trap. Multi-walled carbon nanotubes (MWCNTs) are electrical conductors and their introduction in TiO2 could increase the conductivity. The incorporation of MWCNTs can modify the superhydrophilicity of TiO2. The photoactivity can be improved by reducing the electron-hole recombination rate. MWCNTs play a role in electron transfer and allow to decrease the recombination of electron-hole pairs. Two sol-gel syntheses were studied in alcohol and water respectively. In the alcoholic medium, monolayer films are obtained by dip-coating on alkaline free glass and calcined at 300, 400 or 500°C. The thermal treatment allows to crystallize TiO2 in the anatase form. In the aqueous synthesis, monolayer film are obtained by dip-coating on alkaline free glass. The TiO2 shows already the anatase structure. The characterizations of the samples have confirmed the nanotube presence in the aqueous synthesis, and in the alcoholic synthesis at 300°C and 400°C but not at 500°C. The highest conductivity is obtained from the syntheses in alcohol and the calcination at 300°C. That sample does not exhibit a high photoactivity because of its poor crystallinity. The films without MWCNTs are superhydrophilic but the contact angle increase with the incorporation of MWCNTs. The superhydrophilicity is lost with MWCNTs introduction. MWCNTs increase the roughness, the thickness and the electron transfer of the TiO2 matrix. This induces an enhancement of the photoactivity under UV. The comparison between the two syntheses shows that the alcoholic synthesis (400°C) is the best for pure film. When MWCNTs are introduced, the improvement is higher in the case of aqueous synthesis than in the case of alcoholic synthesis. The aqueous synthesis leads to more active photocatalysts than the alcoholic synthesis. [less ▲]

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See detailHighly dispersed iron xerogel catalysts for p-nitrophenol degradation by photo-Fenton effects
Mahy, Julien ULg; Tasseroul, Ludivine ULg; Zubiaur, Anthony ULg et al

Poster (2014, July)

Since the beginning of the industrial era, the various human activities have increased steadily, leading to a rapid technological development and a high population growth. Thus, the expansion of the ... [more ▼]

Since the beginning of the industrial era, the various human activities have increased steadily, leading to a rapid technological development and a high population growth. Thus, the expansion of the industry has heavily polluted the atmosphere, soil and water with negative consequences for humans and environment [1]. To decrease this pollution, it exists various treatment methods: chemical, physical and biological [2,3]. Among all these methods, a recent way of treatment is the degradation of pollutants in soils or waters by Fenton and photo-Fenton reactions [3] which use H2O2, iron-based compounds and UV light. In this way, several Fe2O3/SiO2 xerogel catalysts were synthesized by cogelation method by hydrolysis and condensation of tetraethoxysilane (TEOS) and 3-(2-aminoethylamino)propyltrimethoxysilane (EDAS) which is able to form a chelate with iron ions [4]. Five samples were synthesized: four samples with different percentage of iron (0.5, 1, 1.5 and 2.5 theoretical wt% confirmed by ICP-AES measurements), and a sample of pure silica. TEM pictures, nitrogen adsorption-desorption and mercury porosimetry measurements have established that EDAS plays a role of nucleating agent of silica particles [5,6] and allows to anchor iron particles inside silica network [4]. Indeed, it results iron nanoparticles of diameter 1-1.5 nm encapsulated in silica particles with sizes of about 10-30 nm in diameter. The species of iron was determined by Mössbauer spectroscopy and only Fe3+ ions were observed in xerogel catalysts. Then, the Fenton and photo-Fenton effect of these catalysts were evaluated on the degradation of p-nitrophenol (PNP) in aqueous medium in different conditions. Results show that Fe2O3/SiO2 xerogels present a photo-Fenton effect with H2O2, reaching with a sample 99 % of degradation after 24 h. [1] M. A. Khan, A. M. Ghouri, Environmental pollution: its effects on life and its remedies, Journal of Arts, Science & Commerce (Vol. 2), 2011, pg 276-285. [2] M. S. Kuyukina , I. B. Ivshina, Biology of rhodococcus: chapter 9, Springer, 2010, pg 232-256. [3] J. J. Pignatello, E. Oliveros, A. MacKay, Advanced Oxidation Processes for Organic Contaminant Destruction Based on the Fenton Reaction and Related Chemistry, Critical Reviews in Environmental Science and Technology (Vol. 36), 2006, pg 1-84. [4] B. Heinrichs, L. Rebbouh, J.W. Geus, S. Lambert, H.C.L. Abbenhuis, F. Grandjean, G.J. Long, J.-P. Pirard, R.A. van Santen, Iron (III) species dispersed in porous silica through sol-gel chemistry, Journal of Non-Crystalline Solids (Vol. 354), 2008, pg 665-672. [5] S. Lambert, C. Alié, J.-P. Pirard, B. Heinrichs, Study of textural properties and nucleation phenomenon in Pd/SiO2 , Ag/SiO2 and Cu/SiO2 cogelled xerogel catalysts, Journal of Non-Crystalline Solids (Vol. 342), 2004, pg 70-81. [6] B. Heinrichs, S. Lambert , N. Job , J.-P. Pirard, in "Catalyst Preparation: Science and Engineering, J. R. Regalbuto (Ed.)", CRC Press, Taylor & Francis Group, Boca Raton, 2007, p. 163-208. [less ▲]

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See detailEffect of metal nanoparticles encapsulated in porous silica on the biphenyl biodegradation by Rhodococcus erythropolis T902.1
Wannoussa, Wissal ULg; Hiligsmann, Serge ULg; Heinrichs, Benoît ULg et al

Poster (2014, May 01)

Biphenyl is stable and highly hydrophobic, thus having a low availability for degrading microorganisms, which need an aqueous environment for their growth. As a consequence, bioremediation processes are ... [more ▼]

Biphenyl is stable and highly hydrophobic, thus having a low availability for degrading microorganisms, which need an aqueous environment for their growth. As a consequence, bioremediation processes are very limited. However, a few studies showed that using a low metal concentration accelerates the biodegradation of pollutants (Yeom and Yoo1997). Nanoparticles are considered as a new generation of compounds to improve environmental remediation and biological processes (Beckers et al. 2013; Zhang 2003). This paper investigated the enhancement effect of nanometre-sized metallic Cu, Ag, Pd or Co, on the biphenyl biodegradation by Rhodococcus erythropolis T902.1. Have been synthesized by a sol–gel process (Lambert et al. 2004). These nanoparticles (NP) of about 2–3 nm were encapsulated in porous silica (SiO2) and were added at low concentration (10-4M) in the M284 minimal medium with 500 ppm biphenyl as source of carbon and energy. The cultures containing Pd or Co produced 30% more biphenyl degraded with a higher Rhodococcus growth than those without NP (positive control) or with silica particles only. On the contrary, the presence of 10-4 M Cu or Ag nanoparticles showed an inhibitory effect on bacterial growth and biphenyl degradation compared to the positive. [less ▲]

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See detailNanostructured catalysts by sol-gel process
Lambert, Stéphanie ULg; Heinrichs, Benoît ULg

Conference (2014, April 25)

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See detailEffect of encapsulated nanoparticles on thermophillic anaerobic digestion
Al-Ahmad, Alaa Eddin ULg; Hiligsmann, Serge ULg; Lambert, Stéphanie ULg et al

Poster (2014, February 07)

Recently, enormous interest has been focused on biological applications of metal nanoparticles NPs due to their small size, high specified surface and their great potential in application to many science ... [more ▼]

Recently, enormous interest has been focused on biological applications of metal nanoparticles NPs due to their small size, high specified surface and their great potential in application to many science fields. The most studied process concerns zero valent palladium and iron NPs improving anaerobic biodegradation of chlorinated hydrocarbons (Windt et al., 2005). Moreover, investigation carried out in our lab showed that iron NPs encapsulated in silicate matrix may enhance hydrogen production by Clostridium butyricum (Beckers et al., 2013). Nevertheless the influences of metal NPs on methane producing anaerobic digestion have seldom been investigated. The present work investigates the enhancement effect of seven different metal NPs on methane production during the thermophilic anaerobic digestion. NPs of Cu, Pd, Pt, Ni, Co, Ag and Fe encapsulated in porous silica (SiO2) to prevent their coagulation and agglomeration, were added at concentration of 10-5mol/L in batch test (125ml serum bottles containing 70mL culture medium with 5g/L acetate monohydrate as the sole carbon substrate). Nickel, cobalt and iron NPs improved methane production from acetate. To confirm the previous results, the NPs were tested at different concentrations (10-4, 10-5, and 10-6 mol/L) with starch and glucose substrates. The results show that the impact increases with the increase of NPs concentrations up to 10-4 mol/L. The modified Gompertz equation was applied to describe the effect of NPs on anaerobic digestion. According to this model, the kinetic of methane production was particularly affected by nanoparticles addition. The values of the maximum methane production rate MPR (ml/day) was significantly higher 72.5% with nickel NPs at a concentration of 10-4 mol/L than the control without NPs. [less ▲]

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See detailDevelopment of alumina xerogel catalysts for biogas cleaning
Claude, Vincent ULg; Heinrichs, Benoît ULg; Toye, Dominique ULg et al

Poster (2014)

This poster resume the synthesis and characterizations of Ni/y-Al2O3 catalysts for the reforming of tars during the bio-syngas purification. The effect of an additionnal organosilane (EDAS) and a ... [more ▼]

This poster resume the synthesis and characterizations of Ni/y-Al2O3 catalysts for the reforming of tars during the bio-syngas purification. The effect of an additionnal organosilane (EDAS) and a surfactant (stearic acid) on the size,the dispersion and the sinterability of the nickel nanoparticles have been investigated. [less ▲]

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See detailPhotocatalytic degradation of water pollutants with visible light-sensitized TiO2 xerogels
Tasseroul, Ludivine ULg; Pirard, Sophie ULg; Lambert, Stéphanie ULg et al

in Récents Progrès en Génie des Procédés (2014), 106

To extend its photocatalytic activity to visible light, TiO2 has been doped in situ through the cogelation sol-gel proces with two dyes : free metal tetra(4-carboxyphenyl)porphyrin and nickel tetra(4 ... [more ▼]

To extend its photocatalytic activity to visible light, TiO2 has been doped in situ through the cogelation sol-gel proces with two dyes : free metal tetra(4-carboxyphenyl)porphyrin and nickel tetra(4-carboxyphenyl)porphyrin. DR and FT-IR spectroscopies have been performed to determine the interaction between porphyrins and TiO2. Cristallinity and specific surface area have been measured by XRD and N2 adsorption. The photoactivity of the doped TiO2 xerogels has been evaluated for p-nitrophenol (a model water pollutant) degradation under visible light and a kinetic study has been performed. The samples allow the degradation of 40% of p-nitrophenol in 6 h which makes them very promising for water decontamination under natural light. A kinetic study of p-nitrophenol degradation with the Ni-doped catalyst has shown that the best kinetic model involves one type of active site corresponding to the hole h+ of electron-hole pairs created at the TiO2 surface by light. The rate determining step consists of the surface reaction between adsorbed p-nitrophenol and adsorbed OH• radicals. [less ▲]

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See detailKinetic study of 4-nitrophenol photocatalytic degradation over a Zn2+ doped TiO2 catalyst prepared through an environmentally friendly aqueous sol–gel process
Malengreaux, Charline ULg; Pirard, Sophie ULg; Bartlett, John et al

in Chemical Engineering Journal (2014), 245

A kinetic study of the photocatalytic degradation of 4-nitrophenol (4-NP) under UV–visible light (330 nm < k < 800 nm) has been performed via a rigorous chemical engineering approach over a Zn2+ doped ... [more ▼]

A kinetic study of the photocatalytic degradation of 4-nitrophenol (4-NP) under UV–visible light (330 nm < k < 800 nm) has been performed via a rigorous chemical engineering approach over a Zn2+ doped TiO2 catalyst prepared through an environmentally friendly aqueous sol–gel process. The experiments have been performed at three temperatures to enable the global activation energy to be estimated. The influence of the illumination intensity has also been considered. The possibility of internal and external diffusion limitations has been studied and the results obtained demonstrated that there is no diffusional limitation during the photocatalytic degradation of the 4-NP using the selected catalyst. Therefore, the apparent specific reaction rate measured corresponds to the actual reaction rate of the chemical reaction. Parameter adjustments show that the kinetic model that provides the best fit to the experimental data corresponds to a first order reaction. A sequence of elementary steps has been considered and a pseudo-steady state approach based upon the stationary state hypothesis for reaction intermediates has been applied to obtain a kinetic rate expression in agreement with the experimental data. The mean values of the reaction rate constant found at 283 K, 288 K and 293 K are respectively equal to k1 = 0.094 ± 0.003 m3 h- 1 kgcatalyst- 1; k2 = 0.119 ± 0.004 m3 h- 1 kgcatalyst- 1 and k3 = 0.150 ± 0.023 m3 h- 1 kg catalyst-1 and the global activation energy of the degradation reaction was evaluated as 40 kJ mol-1. A phenomenological kinetic mechanism is proposed to describe the reaction at a molecular scale. Finally, statistical validations and residuals analysis have been performed to confirm that the first order model is suitable to represent the 4-NP photocatalytic degradation over time. Such studies are essential to design a reactor for water pollutant degradation on an industrial scale. [less ▲]

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See detailComment dépolluer des eaux usées grâce à la lumière du soleil ?
Heinrichs, Benoît ULg

Learning material (2014)

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See detailVisible-light photo-activity of alkali metal doped ZnO
Benhebal, Hadj; Chaib, Messaoud; Malengreaux, Charline ULg et al

in Journal of the Taiwan Institute of Chemical Engineers (2014), 45(1), 249-253

In order to utilize visible light more efficiently in the field of photocatalysis, Li, Na and K-doped ZnO nanoparticles were prepared using a sol–gel method. The obtained samples were characterized by BET ... [more ▼]

In order to utilize visible light more efficiently in the field of photocatalysis, Li, Na and K-doped ZnO nanoparticles were prepared using a sol–gel method. The obtained samples were characterized by BET surface area measurements, X-ray diffraction, scanning electron microscopy and UV–vis analysis. The photocatalytic activity of the photocatalysts was evaluated for the degradation of p-nitrophenol (p-NP) under visible light irradiation. It has been observed that these photocatalysts could be a promising photocatalyst for degradation of organic molecules as compared to transition metal doped ZnO under visible light. Li-doped ZnO is the most active photocatalyst and shows high photocatalytic activity for the degradation of p-nitrophenol (p-NP). The enhanced photocatalytic activity of Li-doped ZnO is mainly due to the electron trapping by lithium metal ions, small particle size, large surface area, and high surface roughness of the photocatalysts. [less ▲]

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See detailEnhancement of thermophillic anaerobic digestion of methane by metal nanoparticles encapsulated in porous silica
Al-Ahmad, Alaa Eddin ULg; Hiligsmann, Serge ULg; Lambert, Stéphanie ULg et al

Poster (2013, December 05)

Increased demand and progressive depletion of fossil fuels, and worldwide concerns about greenhouse gas emissions have resulted in the development of promising technologies for renewable energy production ... [more ▼]

Increased demand and progressive depletion of fossil fuels, and worldwide concerns about greenhouse gas emissions have resulted in the development of promising technologies for renewable energy production. Therefore, potential alternatives for energy generation are intensively studied. One option is the use of biomass feedstock for the production of biogas through anaerobic digestion. This process is a biochemical technological process for the treatment of a wide range of feedstocks (e.g. organic fraction of municipal waste, animal manure and slurry, agricultural crops, etc.) to produce methane-rich biogas which can be used in replacement of fossil fuels in both heat and power generation and as a vehicle fuel. However, there are critical issues, which need to be addressed to make the production of bio-methane techno-economically viable and ecologically acceptable. One of the most important issues is the effect of trace metals addition on anaerobic digestion. These metals can be stimulatory, inhibitory, or even toxic for biochemical reactions, depending on their concentrations. As reported in literature, Ni, Co and Fe are all involved in the methane production biochemical process and serve as cofactors in enzymes which are involved in the biochemistry of methane formation (Zandvoort et al., 2006). Recently, enormous interest has been focused on biological applications of metal nanoparticles NPs due to their small size, high specified surface and their great potential in application to many science fields. The most studied process concerns zero valent palladium and iron NPs improving anaerobic biodegradation of chlorinated hydrocarbons (Windt et al., 2005). Moreover, investigation carried out in our lab showed that iron NPs encapsulated in silicate matrix may enhance hydrogen production by Clostridium butyricum (Beckers et al., 2013). Nevertheless the influences of metal NPs on methane producing anaerobic digestion have seldom been investigated. The present work investigates the enhancement effect of seven different metal NPs on methane production during the thermophilic anaerobic digestion. NPs of Cu, Pd, Pt, Ni, Co, Ag and Fe encapsulated in porous silica (SiO2) to prevent their coagulation and agglomeration, were added at concentration of 10-5mol/L in batch test (125ml serum bottles containing 70mL culture medium with 5g/L acetate monohydrate as the sole carbon substrate. Nickel, cobalt and iron NPs improved methane production from acetate. To confirm the previous results, the NPs were tested at different concentrations (10-4, 10-5, and 10-6 mol/L) with starch and glucose substrates. The results show that the impact increases with the increase of NPs concentrations up to 10-4 mol/L. The modified Gompertz equation was applied to describe the effect of NPs on anaerobic digestion. According to this model, the kinetic of methane production was particularly affected by nanoparticles addition. The values of the maximum methane production rate MPR (ml/day) was significantly higher 72.5% with nickel NPs at a concentration of 10-4 mol/L than the control without NPs. [less ▲]

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See detailDes surfaces fonctionnalisées : la solution par voie liquide
Heinrichs, Benoît ULg

Scientific conference (2013, November 29)

Créer à la surface d’un matériau un film antistatique, antibactérien, autonettoyant ou « easy to clean », un film capable d’épurer l’air ou l’eau. Produire une microbatterie de quelques microns ... [more ▼]

Créer à la surface d’un matériau un film antistatique, antibactérien, autonettoyant ou « easy to clean », un film capable d’épurer l’air ou l’eau. Produire une microbatterie de quelques microns d’épaisseur sur un support. Protéger une surface contre la corrosion. Transférer les propriétés d’une poudre à une surface. Immobiliser un catalyseur sur une surface. … L’industrie est aujourd’hui à la recherche de solutions innovantes pour produire des surfaces fonctionnalisées conférant des propriétés spécifiques et une haute valeur ajoutée aux matériaux et dispositifs qu’elle produit. Focus sur les procédés de dépôt de films par voie liquide, une alternative séduisante aux procédés sous vide. [less ▲]

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