References of "Gaigneaux, Eric"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailAmbient temperature ZrO2-doped TiO2 crystalline photocatalysts: Highly efficient powders and films for water depollution
Mahy, Julien ULiege; Lambert, Stéphanie ULiege; Tilkin, Rémi ULiege et al

in Materials Today Energy (2019), 13

In this paper, several TiO2 materials doped with zirconia precursor (0.7, 1.4, 1.6 and 2.0 mol%) were synthesized by an easy aqueous sol-gel synthesis at ambient temperature. This method consisted in the ... [more ▼]

In this paper, several TiO2 materials doped with zirconia precursor (0.7, 1.4, 1.6 and 2.0 mol%) were synthesized by an easy aqueous sol-gel synthesis at ambient temperature. This method consisted in the peptization of the TiO2 colloid in presence of HNO3. The corresponding pure TiO2 material was also synthesized for comparison. The performances and the physico-chemical properties of these materials were compared to the well-known Evonik P25 photocatalyst. The physico-chemical characterizations showed that nano-crystalline anatase-brookite particles were produced with the sol-gel process, with higher specific surface area than P25 (∼200 m2 g-1 vs. 47 m2 g-1). All samples presented a higher visible absorption than P25. The XPS spectra showed that all the samples were doped with nitrogen and that mixed TiO2–ZrO2 oxide materials were obtained when doping with zirconia precursor. Photoactivity was evaluated through the degradation of p-nitrophenol in water. On the one hand, under UV/visible light, the ZrO2 doping increased the degradation efficiency of the pure TiO2 catalyst due to a better charge separation in the mixed TiO2–ZrO2 oxides. The activity of the sample with the highest dopant content was even higher than the one of P25. On the other hand, under visible light, all samples were much more efficient than P25. This activity shift towards visible range was due to the N-doping of the catalysts, with a slight improvement for the doped ones. Finally, the feasibility of producing films starting from an aqueous suspension of the photocatalyst was assessed on P25, pure TiO2 and the best doped material. The photoactivity of these films, evaluated on the degradation of methylene blue under UV-A light, showed that the sample with the highest dopant concentration had an efficiency 4 times higher than pure TiO2 and 20 times higher than P25. [less ▲]

Detailed reference viewed: 17 (10 ULiège)
Peer Reviewed
See detailAqueous N-Doped TiO2 Catalysts for Visible Light Photocatalytic Applications
Mahy, Julien ULiege; Cerfontaine, Vincent; Poelman, Dirk et al

Poster (2018, November)

In this work, TiO2 prepared with an aqueous sol-gel synthesis by peptization process is doped with nitrogen precursor to extend its activity towards the visible region. Three N-precursors are used: urea ... [more ▼]

In this work, TiO2 prepared with an aqueous sol-gel synthesis by peptization process is doped with nitrogen precursor to extend its activity towards the visible region. Three N-precursors are used: urea, ethylenediamine and triethylamine. Different molar N/Ti ratios are tested and the synthesis is adapted for each dopant. For urea- and trimethylamine-doped samples, anatase-brookite TiO2 nanoparticles of 6–8 nm are formed, with a specific surface area between 200 and 275 m2 g−1. In ethylenediamine-doped samples, the formation of rutile phase is observed, and TiO2 nanoparticles of 6–8 nm with a specific surface area between 185 and 240 m2 g−1 are obtained. X-ray photoelectron spectroscopy (XPS) and diffuse reflectance measurements show the incorporation of nitrogen in TiO2 materials through Ti–O–N bonds allowing light absorption in the visible region. Photocatalytic tests on the remediation of water polluted with p-nitrophenol show a marked improvement for all doped catalysts under visible light. The optimum doping, taking into account cost, activity and ease of synthesis, is up-scaled to a volume of 5 L and compared to commercial Degussa P25 material. This up-scaled sample shows similar properties compared to the lab-scale sample, i.e., a photoactivity 4 times higher than commercial P25. [less ▲]

Detailed reference viewed: 30 (3 ULiège)
Full Text
Peer Reviewed
See detailEfficient P/N and Ag-doped titania for the photocatalytic degradation of waste water organic pollutants
Mahy, Julien ULiege; Bodson, Céline; Cerfontaine, Vincent et al

Conference (2018, October 04)

Detailed reference viewed: 30 (2 ULiège)
Full Text
Peer Reviewed
See detailHighly Efficient Low-Temperature N-Doped TiO2 Catalysts for Visible Light Photocatalytic Applications
Mahy, Julien ULiege; Cerfontaine, Vincent; Poelman, Dirk et al

in Materials (2018), 11(584),

In this paper, TiO2 prepared with an aqueous sol-gel synthesis by peptization process is doped with nitrogen precursor to extend its activity towards the visible region. Three N-precursors are used: urea ... [more ▼]

In this paper, TiO2 prepared with an aqueous sol-gel synthesis by peptization process is doped with nitrogen precursor to extend its activity towards the visible region. Three N-precursors are used: urea, ethylenediamine and triethylamine. Different molar N/Ti ratios are tested and the synthesis is adapted for each dopant. For urea- and trimethylamine-doped samples, anatase-brookite TiO2 nanoparticles of 6–8 nm are formed, with a specific surface area between 200 and 275 m2·g−1. In ethylenediamine-doped samples, the formation of rutile phase is observed, and TiO2 nanoparticles of 6–8 nm with a specific surface area between 185 and 240 m2·g−1 are obtained. X-ray photoelectron spectroscopy (XPS) and diffuse reflectance measurements show the incorporation of nitrogen in TiO2 materials through Ti–O–N bonds allowing light absorption in the visible region. Photocatalytic tests on the remediation of water polluted with p-nitrophenol show a marked improvement for all doped catalysts under visible light. The optimum doping, taking into account cost, activity and ease of synthesis, is up-scaled to a volume of 5 L and compared to commercial Degussa P25 material. This up-scaled sample shows similar properties compared to the lab-scale sample, i.e., a photoactivity 4 times higher than commercial P25. [less ▲]

Detailed reference viewed: 41 (7 ULiège)
Full Text
Peer Reviewed
See detailAg/SiO2 and Cu/SiO2 cogelled xerogel catalysts for benzene combustion and 2-butanol deshydrogenation
Mahy, Julien ULiege; Claude, Vincent ULiege; Tasseroul, Ludivine ULiege et al

Poster (2016, June 08)

Tars are recognized as major impurities when biomass is gazified into Syngas (mixture CO + H2) or when the methane reforming was produced from sustainaible reagents [1]. Therefore, fundamental knowledge ... [more ▼]

Tars are recognized as major impurities when biomass is gazified into Syngas (mixture CO + H2) or when the methane reforming was produced from sustainaible reagents [1]. Therefore, fundamental knowledge of catalytic oxidation and deshydrogenation mechanisms can be valuable to develop effective methods to control syngas or methane pollution. A very important concern about cogelled catalysts is the accessibility of the active centers. Because the silver and copper is located inside silica particles, there is a risk that it may not be accessible. In the case of benzene oxidation, it was observed that the specific activity (mol s-1 g-1Ag) of Ag/SiO2 and Cu/SiO2 catalysts increases when the silver or copper loading decreases (Fig. 1). In fact, visual observations by TEM showed that in samples Ag0.25, Ag0.45, Ag1.05 and Cu1.00, there are not silver or copper particles located on silica particles external surface and then the metal dispersion values are greater in these samples. So, it is the proof that Ag and Cu particles located inside the silica particles are accessible for benzene in this catalytic system. In the case of 2-butanol dehydrogenation, the specific activity of Cu/SiO2 catalysts increases when the copper loading increases or when the metal dispersion values decreases (Fig. 2). However, in Cu1.00 sample, copper particles inside silica particles only are observed by TEM. It seems that these metallic particles are accessible for 2-butanol in this catalytic system. [less ▲]

Detailed reference viewed: 130 (6 ULiège)
Full Text
Peer Reviewed
See detailDevelopment of alumina xerogel catalysts for biogas cleaning
Claude, Vincent ULiege; Heinrichs, Benoît ULiege; Toye, Dominique ULiege 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 ▲]

Detailed reference viewed: 76 (15 ULiège)
Full Text
Peer Reviewed
See detailMesoporous Lithium Vanadium Oxide as Thin Film Electrode for Lithium-Ion Batteries: Comparison between Direct Synthesis of LiV2O5 and Electrochemical Lithium Intercalation in V2O5
Caes, Sébastien ULiege; Arrebola, Jose Carlos; Krins, Natacha ULiege et al

in Journal of Materials Chemistry A (2014), 2

Research in the field of lithium-ion batteries favours electrode materials with high surface area. In this context, this paper is dedicated to mesoporous thin films (MTFs) and compares the electrochemical ... [more ▼]

Research in the field of lithium-ion batteries favours electrode materials with high surface area. In this context, this paper is dedicated to mesoporous thin films (MTFs) and compares the electrochemical performance of g-LiV2O5 MTFs with post-synthesis electrochemical lithium intercalation in a-V2O5 MTFs. Formation of vanadium oxide MTFs by soft-chemistry is notoriously difficult. However, it is shown that wormlike vanadium oxide (V–O) and lithium vanadium oxide (Li–V–O) MTFs can be obtained on silicon substrates by a direct sol–gel soft-templating route (evaporation-induced micelle assembly) using a polystyrene-block-poly(ethylene oxide) (PS-b-PEO) structuring agent. Heat treatment for 1 minute at 400 C (Li–V–O system) or 30 minutes at 350 C (V–O system) leads to the crystallization of g-LiV2O5 or a-V2O5, respectively. These calcination conditions ensure the degradation of the structuring agent while preventing the collapse of the mesostructure, yielding MTFs with pore size diameter in the 30–35 nm range. Using the same set of synthesis conditions, films can be deposited on conductive glass substrates for electrochemical investigation: the a-V2O5 films display better specific capacities, while the cyclability is good for both compositions, even at a current density as high as 30 C-rate. [less ▲]

Detailed reference viewed: 119 (22 ULiège)
Full Text
Peer Reviewed
See detailCharacterization of H3+xPMo12 xVxO40 heteropolyacids supported on HMS mesoporous molecular sieve and their catalytic performance in propene oxidation
Benadji, Siham; Eloy, Pierre; Léonard, Alexandre ULiege et al

in Microporous and Mesoporous Materials (2012), 154

Detailed reference viewed: 23 (1 ULiège)
Full Text
Peer Reviewed
See detailInvestigation of the preparation and activity of gold catalysts in the total oxidation of n-hexane
Cellier Caroline; Lambert, Stéphanie ULiege; Gaigneaux Eric et al

in Applied Catalysis B: Environmental (2007), 70

The factors affecting the preparation of Au/TiO2 catalysts and their activity in the total oxidation of n-hexane were investigated. The mechanism of gold deposition–precipitation is discussed through ... [more ▼]

The factors affecting the preparation of Au/TiO2 catalysts and their activity in the total oxidation of n-hexane were investigated. The mechanism of gold deposition–precipitation is discussed through comparison of the samples prepared by this method and others prepared by anion adsorption method. The influence of the pH and of the origin of TiO2 support used are additionally addressed. The difference of gold dispersion observed between the two methods is attributed to a difference of mobility of the gold precursors during the thermal treatment rather than to a difference of dispersion over the uncalcined samples. The mechanism of gold deposition–precipitation actually involves the reactions of gold hydroxy-chloride species with the surface. Another part of the work, thus, concerned the use of the deposition–precipitation method to prepare a Au/MnO2 catalyst. It is shown that the activity of g-MnO2 is directly proportional to its surface area and that the deposition–precipitation procedure decreases the surface and activity of MnO2. However, the deposition of gold allows to avoid a too deep sintering of g-MnO2 and, thus, helps to somehow preserve its activity. [less ▲]

Detailed reference viewed: 30 (0 ULiège)
Full Text
Peer Reviewed
See detailOn the structure-sensitivity of 2-butanol dehydrogenation over Cu/SiO2 cogelled xerogel catalysts
Lambert, Stéphanie ULiege; Cellier, Caroline; Ferauche, Fabrice et al

in Catalysis Communications (2007), 8

Detailed reference viewed: 59 (2 ULiège)
Peer Reviewed
See detailOptimized conditions for the preparation of Pt supported catalysts by deposition-precipitation
Cellier Caroline; Lambert, Stéphanie ULiege; Ruaux Vincent et al

Poster (2006, September)

Detailed reference viewed: 32 (0 ULiège)
Full Text
Peer Reviewed
See detailScreening of noble metal and transition metal oxide catalysts for the removal of VOCs, N-VOCs and S-VOCS
Cellier, Caroline; Lambert, Stéphanie ULiege; Gaigneaux, Eric et al

Poster (2005, June 29)

Detailed reference viewed: 40 (0 ULiège)
Peer Reviewed
See detailInvestigation of the preparation and activity of gold catalysts in the total oxidation of n-hexane
Cellier Caroline; Lambert, Stéphanie ULiege; Gaigneaux Eric et al

Poster (2005, June)

Detailed reference viewed: 12 (0 ULiège)