References of "Lambert, Stéphanie"
     in
Bookmark and Share    
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 277 (62 ULg)
Full Text
Peer Reviewed
See detailPhotocatalytic Oxidative Treatment of Waste Water contamined with Pharmaceutical Products
Vreuls, Christelle; Wilmot, Annick; Cludts, Marc et al

Poster (2015, July)

Detailed reference viewed: 17 (4 ULg)
Full Text
Peer Reviewed
See detailEffect of iron nanoparticles synthesized by a sol-gel process on Rhodococcus erythropolis T902.1 for biphenyl degradation
Wannoussa, Wissal ULg; Masy, Thibaut ULg; Lambert, Stéphanie ULg et al

in Journal of Water Resource and Protection (2015), 7

Nanoparticles (NPS) are considered as a new generation of compounds to improve environmental remediation and biological processes. The aim of this study is to investigate the effect of iron NPS ... [more ▼]

Nanoparticles (NPS) are considered as a new generation of compounds to improve environmental remediation and biological processes. The aim of this study is to investigate the effect of iron NPS encapsulated in porous silica (SiO2) on the biphenyl biodegradation by Rhodococcus erythropolis T902.1 (RT902.1). The iron NPS (major iron oxide FexOy form) were dispersed in the porosity of a SiO2 support synthesized by sol-gel process. These Fe/SiO2 NPS offer a stimulating effect on the biodegradation rate of biphenyl, an organic pollutant that is very stable and water-insoluble. This positive impact of NPS on the microbial biodegradation was found to be dependent on the NPS concentration ranging from 10−6 M to 10−4 M. After 18 days of incubation the cultures containing NPS at a concentration of 10−4 M of iron improved RT902.1 growth and degraded 35% more biphenyl than those without NPS (positive control) or with the sole SiO2 particles. Though the microorganism could not interact directly with the insoluble iron NPS, the results show that about 10% and 35% of the initial 10−4 M iron NPS encapsulated in the SiO2 matrix would be incorporated inside or adsorbed on the cell surface respectively and 35% would be released in the supernatant. These results suggest that RT902.1 would produce siderophore-like molecules to attract iron from the porous silica matrix. [less ▲]

Detailed reference viewed: 111 (71 ULg)
Full Text
Peer Reviewed
See detailAmélioration de la biodégradation du biphényle par Rhodococcus erythropolis t902.1 en présence de Fe2O3 et de nanoparticules de fer encapsulées dans un xérogel de silice
wanoussa; Hiligsmann, Serge ULg; Tasseroul, Ludivine ULg et al

in Déchets Sciences et Techniques (2015), 69

In this work, the effect of iron oxide particles Fe2O3 and iron nanoparticles encapsulated in a porous silica matrix (xerogel Fe/SiO2) was investigated on biphenyl biodegradation by the strain Rhodococcus ... [more ▼]

In this work, the effect of iron oxide particles Fe2O3 and iron nanoparticles encapsulated in a porous silica matrix (xerogel Fe/SiO2) was investigated on biphenyl biodegradation by the strain Rhodococcus erythropolis T902.1. After 18 days of incubation biodegradation yields of 75% and 85% were achieved respectively in presence of non-autoclaved or autoclaved xerogel Fe/SiO2 at 10-5 M iron. These results are 42 and 60 % higher than in standard conditions without nanoparticles. They suggest that the autoclave procedure lead to the release of some iron less anchored in the silica matrix. This study highlights that siderophore production by Rhodococcus erythropolis T902.1 would be related to the presence of iron nanoparticles in the culture. It suggests that the production of these strong chelating compounds decreases with increase of iron release from xerogel Fe/SiO2. Moreover, most of the surfactants synthesized by Rhodococcus erythropolis T902.1 which are glycolipids containing trehalose (hexose), would be linked to cell surface and not excreted in the culture medium; the biomass hexose content also increased by 85% in presence of iron nanoparticles. [less ▲]

Detailed reference viewed: 22 (2 ULg)
Full Text
Peer Reviewed
See detailPhotocatalytic decolorization of Gentian Violet with Na-doped (SnO2 and ZnO)
Benhebal, Hadj; Chaib, Messaoud; Crine, Michel ULg et al

in Chiang Mai Journal of Sciences (2015), 42

Photocatalysis is a technique used for the purification and decolorization of water. In this work, the photocatalytic decolorization of aqueous solutions of Gentian Violet has been investigated. The ... [more ▼]

Photocatalysis is a technique used for the purification and decolorization of water. In this work, the photocatalytic decolorization of aqueous solutions of Gentian Violet has been investigated. The photocatalysts used for the study are tin dioxide (SnO2) and zinc oxide (ZnO) doped with sodium and prepared by sol-gel process. Photocatalysts were synthesised by sol-gel process and characterized by several techniques such as X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Brunauer, Emmett and Teller (BET) method and UV-vis Spectroscopy. The results of photocatalytic activity of gentian violet degradation under ultraviolet irradiation, indicated that the synthesised photocatalyst exhibit good photocatalytic performance. [less ▲]

Detailed reference viewed: 16 (1 ULg)
Full Text
Peer Reviewed
See detailEffect of metal ions and metal nanoparticles encapsulated in porous silica on biodegradation kinetics for biphenyl
Wannoussa, Wissal; Hiligsmann, Serge ULg; Masy, Thibaut ULg et al

in Journal of Sol-Gel Science and Technology (2015), 75

Biodegradation of biphenyl was carried out by Rhodococcus erythropolis T902.1 in presence of nanometer-sized metallic (Co, Pd, Ag and Cu) nanoparticles (NPS) synthesized by the sol-gel process. In order ... [more ▼]

Biodegradation of biphenyl was carried out by Rhodococcus erythropolis T902.1 in presence of nanometer-sized metallic (Co, Pd, Ag and Cu) nanoparticles (NPS) synthesized by the sol-gel process. In order to prevent their agglomeration, the metallic NPs (1-2 nm diameter) were anchored inside microporous silica crystallites and named Co/SiO2, Pd/SiO2, Ag/SiO2 and Cu/SiO2 samples respectively. They were added at low concentrations of 10-6 M, 10-5 M and 10-4 M of metal in the culture medium and their impact was compared with that of the simple metal ions added as cobalt, palladium, silver or copper salts. The cultures containing Pd/SiO2 or Co/SiO2 samples at 10-4 M of metal achieved a 50% higher biphenyl degradation yield after 18 days of incubation and improved Rhodococcus erythropolis T902.1 growth compared with those without (positive control) or with silica particles only. The highest biodegradation performance, i.e. 107±3 ppm/day, which was about 85% higher than in control conditions without NPs, was recorded in 250 ml baffled flasks stirred at 150 rpm with Co/SiO2 sample at 10-4 M Co. Furthermore, the stimulating effect of NPs on biphenyl biodegradation seems to also depend on the thermal treatment conditions applied to NPs since the experimental results indicated that, after calcination, the cobalt oxide NPs at a concentration of 10-4 M were more effective than the reduced cobalt NPs with a degradation yield of 81±1% and 77±2% respectively after 18 days. On the other hand, the results showed that the addition of 10-4 M of Cu2+ or Ag+ ions or the addition of Cu/SiO2 or Ag/SiO2 samples at 10-4 M of metal have an inhibitory effect on biphenyl biodegradation. However, Cu+2 and Ag+ ions were more toxic to the Rhodococcus erythropolis T902.1 bacteria than the respective Cu or Ag NPS anchored inside silica particles. Moreover, this work showed that in these conditions, the activity of catechol 1, 2-dioxygenase (a critical enzyme in aromatic biodegradation pathway) was severely inhibited, whereas the presence of 10-4 M of Co2+ ions or Co/SiO2 sample stimulated the enzyme activity compared to the conditions without NPs. [less ▲]

Detailed reference viewed: 16 (3 ULg)
Full Text
Peer Reviewed
See detailEffect of metal ions and metal nanoparticles encapsulated in porous silica on biphenyl biodegradation by Rhodococcus erythropolis T902.1
Wannoussa, Wissal ULg; Hiligsmann, Serge ULg; Tasseroul, Ludivine ULg et al

in Journal of Sol-Gel Science and Technology (2015)

Biodegradation of biphenyl was carried out by Rhodococcus erythropolis T902.1 in presence ofnanometer-sized metallic (Co, Pd, Ag and Cu) nanoparticles (NPS) synthesized by the sol-gel process. In order to ... [more ▼]

Biodegradation of biphenyl was carried out by Rhodococcus erythropolis T902.1 in presence ofnanometer-sized metallic (Co, Pd, Ag and Cu) nanoparticles (NPS) synthesized by the sol-gel process. In order to prevent their agglomeration, the metallic NPs (1-2 nm diameter) were anchored inside microporous silica crystallites and named Co/SiO2, Pd/SiO2, Ag/SiO2 and Cu/SiO2 samples respectively. They were added at low concentrations of 10-6 M, 10-5 M and 10-4 M of metal in the culture medium and their impact was compared with that of the simple metal ions added as cobalt, palladium, silver or copper salts. The cultures containing Pd/SiO2 or Co/SiO2 samples at 10-4 M of metal achieved a 50% higher biphenyl degradation yield after 18 days of incubation and improved Rhodococcus erythropolis T902.1 growth compared with those without (positive control) or with silica particles only. The highest biodegradation performance, i.e. 107 ±3 ppm/day, which was about 85% higher than in control conditions without NPs, was recorded in 250 ml baffled flasks stirred at 150 rpm with Co/SiO2 sample at 10-4 M Co. Furthermore, the stimulating effect of NPs on biphenyl biodegradation seems to also depend on the thermal treatment conditions applied to NPs since the experimental results indicated that, after calcination, the cobalt oxide NPs at a concentration of 10-4 M were more effective than the reduced cobalt NPs with a degradation yield of 81 ±1% and 77 ±2% respectively after 18 days. On the other hand, the results showed that the addition of 10-4 M of Cu2+ or Ag+ ions or the addition of Cu/SiO2 or Ag/SiO2 samples at 10-4 M of metal have an inhibitory effect on biphenyl biodegradation. However, Cu2+ and Ag+ ions were more toxic to the Rhodococcus erythropolis T902.1 bacteria than the respective Cu or Ag NPS anchored inside silica particles. Moreover, this work showed that in these conditions, the activity of catechol 1, 2-dioxygenase (a critical enzyme in aromatic biodegradation pathway) was severely inhibited, whereas the presence of 10-4 M of Co2+ ions or Co/SiO2 sample stimulated the enzyme activity compared to the conditions without NPs. [less ▲]

Detailed reference viewed: 75 (39 ULg)
Full Text
Peer Reviewed
See detailDesign of Pt/carbon xerogel catalysts for PEM fuel cells
Job, Nathalie ULg; Lambert, Stéphanie ULg; Zubiaur, Anthony ULg et al

in Catalysts (2015), 5

Detailed reference viewed: 22 (4 ULg)
Full Text
See detailReformage catalytique du toluène
Claude, Vincent ULg; Lambert, Stéphanie ULg; Courson, Claire

Poster (2014, October 23)

This poster summarizes results obtained for the catalytic reforming of tar in the oultlet gas of a biomass gasifier. All samples were synthesized with aluminum nitrate and an organosilane (EDAS) in order ... [more ▼]

This poster summarizes results obtained for the catalytic reforming of tar in the oultlet gas of a biomass gasifier. All samples were synthesized with aluminum nitrate and an organosilane (EDAS) in order to enhance the metallic dispersion and surface area. Three different compositions have been studied (Al2O3-SiO2; Al2O3-SiO2+2%wt Ni; Al2O3-SiO2+10%wt Fe). The catalytic tests highlight the fact that the sample containing 2%Ni wt is the more appropriate in our conditions. [less ▲]

Detailed reference viewed: 19 (5 ULg)
See detailLes nanoparticules et les micro-organismes au service de la dépollution des sols
Lavigne, Benoît; Lambert, Stéphanie ULg

Scientific conference (2014, October 14)

Detailed reference viewed: 63 (4 ULg)
Full Text
Peer Reviewed
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 ▲]

Detailed reference viewed: 98 (31 ULg)
Full Text
Peer Reviewed
See detailSynthesis, Surface characterization and photocatalytic activity of TiO2 supported on almond shell activated carbon
Omri, Abdessalem; Lambert, Stéphanie ULg; Geens, Jérémy ULg et al

in Journal of Materials Science & Technology (2014), 30(9), 894-902

Three types of photocatalysts were synthesized by metal organic chemical vapor deposition and impregnation methods using the almond shell activated carbon as support. These photocatalysts denoted by (TiO2 ... [more ▼]

Three types of photocatalysts were synthesized by metal organic chemical vapor deposition and impregnation methods using the almond shell activated carbon as support. These photocatalysts denoted by (TiO2/ASAC (V), TiO2/ASAC (I1) and TiO2/ASAC (I2)) were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), diffuse reflectance spectroscopy (DRS) and nitrogen adsorptionedesorption isotherms. SEM observation shows that TiO2 was deposited on activated carbon surface. XRD results confirm that TiO2 existed in a mixture of anatase and rutile phases. The DRS spectra show the characteristic absorption edge of TiO2 at approximate 380 nm corresponding to the optical band gap of 3.26 eV. Besides, FTIR spectrum indicated the presence of (TieO) groups. The specific surface area of photocatalysts decreased drastically in comparison with the original activated carbon. The catalysts were very efficient for the photodegradation of total organic carbon (TOC) from industrial phosphoric acid solution under UV irradiation. The kinetics of photocatalytic TOC degradation was found to follow a pseudofirst- order model. The prepared TiO2/ASAC showed high photoactivity for the photodegradation of TOC in the following order: TiO2/ASAC (V) > TiO2/ASAC (I1) > TiO2/ASAC (I2) > ASAC > TiO2 (P25). [less ▲]

Detailed reference viewed: 243 (8 ULg)
Full Text
See detailSynthesis of Pt/Carbon Xerogel Electrocatalysts for PEM Fuel Cells by the Multiple SEA Method
Zubiaur, Anthony ULg; Chatenet, Marian; Maillard, Frédéric et al

Poster (2014, July)

Detailed reference viewed: 29 (1 ULg)
Peer Reviewed
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 ▲]

Detailed reference viewed: 120 (25 ULg)
Full Text
Peer Reviewed
See detailDesign of Pt/carbon xerogel catalysts for PEM fuel cells
Job, Nathalie ULg; Lambert, Stéphanie ULg; Zubiaur, Anthony ULg et al

Conference (2014, July)

Detailed reference viewed: 14 (0 ULg)
Full Text
Peer Reviewed
See detailUsing the Multiple SEA Method to Synthesize Pt/Carbon Xerogel Electrocatalysts for PEMFC Applications
Zubiaur, Anthony ULg; Chatenet, Marian; Maillard, Frédéric et al

in Fuel Cells - From Fundamentals to Systems (2014), 14(3), 343-349

Detailed reference viewed: 52 (32 ULg)