References of "Belet, Artium"
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See detailHeterogenization of a cyclocarbonation catalyst: optimization and kinetic study
Léonard, Géraldine L.-M.; Belet, Artium ULiege; Grignard, Bruno ULiege et al

in Catalysis Today (in press)

Different types of heterogeneous catalysts designed for a cyclocarbonation reaction between an epoxidized source and CO2 under supercritical conditions have been synthesized. The process implied a ... [more ▼]

Different types of heterogeneous catalysts designed for a cyclocarbonation reaction between an epoxidized source and CO2 under supercritical conditions have been synthesized. The process implied a quaternization step where a (haloalkyl)trimethoxysilane reacted with tributylamine leading to a tributyl(trimethoxysilylalkyl)ammonium halide, with iodine and bromine as halogens. Then, a grafting step onto commercial fumed silica through condensation reaction between the silane part and Si-OH surficial groups provided the immobilized catalyst. The efficiency of grafting has been validated by liquid 1H NMR, solid 29Si NMR and TG-DSC-MS analyzes. The benchmark cyclocarbonation reaction of polyethylene glycol diglycidylether at 80 °C and 100 bar during 4 h showed that the best immobilized catalyst was tributylpropylammonium iodide (IC3Q-EH5). It has also been shown that immobilization provided -surprisingly !- better conversions than the corresponding homogeneous catalyst’s: this phenomenon has been explained through an epoxide-ring-opening activating effect thanks to Si-OH surficial groups. Furthermore, kinetic studies performed by in situ Raman spectroscopy on IC3Q-EH5 showed that temperature had a strong influence on the yield of the reaction while CO2 pressure had only a small effect. Recycling of the catalyst has also been considered, but no precise conclusions could be conducted because of the high catalyst dispersion. Finally, the addition of a fluorinated alcohol co-catalyst allowed obtaining a similar yield but at 80 °C and 55 bar during only 2,5 h with the best candidate. [less ▲]

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See detailSol-gel syntheses of photocatalysts for the removal of pharmaceutical products in water
Belet, Artium ULiege; Wolfs, Cédric ULiege; Mahy, Julien ULiege et al

in Nanomaterials (2019), 9

A screening study on seven photocatalysts was performed to identify the best candidate for pharmaceutical products degradation in water. Photocatalysts were deposited as thin films through a sol-gel ... [more ▼]

A screening study on seven photocatalysts was performed to identify the best candidate for pharmaceutical products degradation in water. Photocatalysts were deposited as thin films through a sol-gel process and subsequent dip-coating on glass slides. The efficiency of each photocatalyst was assessed through the degradation of methylene blue first, and then, through the degradation of fifteen different pharmaceutical products. Two main types of synthesis methods were considered: aqueous syntheses, where the reaction takes place in water, and organic syntheses, where reactions take place in an organic solvent and only a stoichiometric amount of water is added to the reaction medium. Photocatalysts synthesized via aqueous sol-gel routes showed relatively lower degradation efficiencies; however, the organic route required a calcination step at high temperature to form the photoactive crystalline phase, while the aqueous route did not. The best performances for the degradation of pharmaceuticals arose when Evonik P25 and silver nanoparticles were added to TiO2, which was synthesized using an organic solvent. In the case of methylene blue degradation, TiO2 modified with Evonik P25 and TiO2 doped with MnO2 nanoparticles were the two best candidates. [less ▲]

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See detailHETEROGENIZATION OF A CYCLOCARBONATION CATALYST
Léonard, Géraldine; Belet, Artium ULiege; Grignard, Bruno ULiege et al

Poster (2018, July 09)

Nowadays, in order to limit the global warming, CO2 emissions have to be drastically reduced. A first way is to use CO2 as a renewable C1 feedstock that could be industrially valorized to produce added ... [more ▼]

Nowadays, in order to limit the global warming, CO2 emissions have to be drastically reduced. A first way is to use CO2 as a renewable C1 feedstock that could be industrially valorized to produce added value chemicals such as urea, methanol, salicylic acid and cyclic carbonates. Among those compounds, cyclic carbonates are used in a wide range of applications: electrolytes for Li-ion batteries, solvent, intermediates in pharmaceutical and cosmetic industries and also monomers of non-isocyanates polyurethanes (niPU). A second approach, in order to reduce the household energetic consumption and save energy, is insulating using polyurethane (PU) materials. In fact, in comparison with glass wool, rock wool, wood and hemp, PU is one of the most efficient materials for thermal insulation as it exhibits very low thermal conductivity values. But because of the high toxicity of the isocyanate monomer, a new alternative routine using the copolymerization of cyclic carbonates with diamines to produce niPU is a promising solution. In this work, different types of heterogeneous catalysts have been synthesized toward a cyclocarbonation reaction between CO2 in a supercritical state (scCO2) and an epoxidized source (polyethylene glycol diglycidylether (PEG-500), for 4h at 80°C and 100 bar of pressure). First, optimal organic salt-based catalysts were chosen for this reaction: tetrabutylammonium iodide (TBAI) and tetrabutylammonium bromide (TBABr). These catalysts were immobilized onto a silica-based support by condensation reaction between silane and surficial silanol groups (R2). The best support was identified being EH-5 fumed silica (from CAB-O-SIL) because of its large specific area and its higher mesoporous to microporous volume ratio. Afterwards, it has been demonstrated that better grafting percentages as well as a better conversions could be obtained if the quaternization (R1) step is performed before the grafting step (R2). Then, it has been shown that - surprisingly ! - the best candidate (FIGURE 1 : IC3Q-EH-5) gives better conversions than the corresponding homogeneous catalyst ! This phenomenon has been explained through an epoxy-ring-opening activator effect thanks to the surficial silanol groups. Finally, the up-scaling of the IC3Q-EH-5 from 5g to 60g was successfully performed, as well as the use of a fluorinated alcohol co-catalyst, which allows reducing the operation conditions from 100 bar to 55 bar and from 240 min. to 150 min. Characterizations were made by liquid 1H NMR for cyclocarbonation yield, by solid 29Si NMR for organic-to-inorganic bonds description, by TG-DSC-MS for grafting efficiency and catalyst description and by nitrogen adsorption/desorption for support description. Kinetic studies of cyclocarbonation with or without a co-catalyst were further performed by in situ Raman spectroscopy. [less ▲]

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See detailAdvanced oxidative treatment for wastewater contaminated by micropollutants
Wolfs, Cédric ULiege; Belet, Artium ULiege; Mertes, Alexander ULiege et al

Poster (2018, July 09)

Micropollutants are introduced into the environment by domestic, industrial or hospital waste waters. Some of them are poorly removed by classical waste water treatment plants. The project plans to ... [more ▼]

Micropollutants are introduced into the environment by domestic, industrial or hospital waste waters. Some of them are poorly removed by classical waste water treatment plants. The project plans to develop an efficient and versatile oxidative method of removal of these micropollutants inside a waste water treatment plant (WWTP). The main technique developed is photocatalysis, where a material causes chemical reactions when exposed to light. [less ▲]

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See detailAdvanced oxidative treatment for waste water contamined by pharmaceutical products
Belet, Artium ULiege; Vreuls, Christelle; Gillard, Nathalie et al

Poster (2017, September 07)

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See detailAdvanced oxidative treatment for waste water contaminated by pharmaceutical products
Wolfs, Cédric ULiege; Vreuls, Christelle; Gillard, Nathalie et al

Conference (2017, July 12)

The objective of this study is to determine operational processes for advanced oxidative treatment of waste waters contaminated with pharmaceutical products. The aim is to validate a physico-chemical ... [more ▼]

The objective of this study is to determine operational processes for advanced oxidative treatment of waste waters contaminated with pharmaceutical products. The aim is to validate a physico-chemical process that has to be placed downstream a classical biological treatment in existing waste water treatment plants (domestic, industrial or hospital). [less ▲]

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See detailAdvanced oxidative treatment for waste water contamined by pharmaceutical products
Belet, Artium ULiege; Vreuls, Christelle; Gillard, Nathalie et al

Conference (2017, July 07)

The objective of this study is to determine operational processes for advanced oxidative treatment of waste waters contaminated with Pharmaceutical Products (PPs). The aim is to validate a physico ... [more ▼]

The objective of this study is to determine operational processes for advanced oxidative treatment of waste waters contaminated with Pharmaceutical Products (PPs). The aim is to validate a physico-chemical process combining ozonation and photocatalysis and that has to be placed downstream a classical biological treatment in existing waste water treatment plants (WWTP - domestic, industrial or hospital). [less ▲]

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