MIL Metal-Organic Frameworks: Synthesis, Post-Synthetic Modifications, and Applications

Au cours des dernières décennies, la communauté scientifique du monde entier a assisté à l’émergence d’une nouvelle classe de matériaux poreux aux caractéristiques structurelles et chimiques incontestablement uniques. La découverte des charpentes organométalliques (MOF) a impressionné la communauté des zéolites et des matériaux poreux. La grande expansion dans ce domaine a comblé une lacune dans les dimensions des solides poreux. Depuis lors, les MOF sont en concurrence avec les zéolites et les oxydes métalliques dans diverses applications, notamment la catalyse, l’adsorption et la séparation de gaz, la photocatalyse et la détection. Dans cette thèse, les travaux de recherche ont été orientés vers la synthèse, la caractérisation, la modification post-synthétique et les applications de charpentes métalorganiques. Ici, nous avons sélectionné trois des MOF de type MIL bien connus. Ils possèdent tous une structure 3D construite à partir d’ions métalliques trivalents et du lieur ditopique de l’acide benzènedicarboxylique-1,4 (H2BDC); cependant, ils occupent des filets différents.---------- ABSTRACT Over the past decades, the scientific community all over the world witnessed the emergence of a new class of porous materials with unquestionably unique structural and chemical features. The discovery of metal-organic frameworks (MOFs) impressed the community of zeolites and porous materials. The great expansion in this field fulfilled a gap in the dimensions of porous solids. Since then, MOFs have been competing with zeolites and metal oxides in various applications, including catalysis, gas-adsorption and separation, photocatalysis, and sensing. In this thesis, research studies were directed towards the synthesis, characterization, postsynthetic modification, and applications of metal-organic frameworks. Here, we selected three of the well-known MIL-type MOFs. They all possess a 3D structure built from trivalent metal ions and the ditopic 1,4-Benzenedicarboxylic acid linker (H2BDC); however, they occupy different nets

Sonocatalytic Biodiesel Transesterification to Produce a Lubricant

The growth of the machinery and automotive industry drives interest toward the production of biolubricants due to their better lubricating properties and their low carbon footprint compared to petroleum-based lubricants. However, their traditional synthesis is long and energy-intensive. We intensified the production of biolubricants from canola oil methyl esters using ultrasound. NaOH catalyzed the transesterification of two polyalcohols (propylene and trimethylene glycols). We varied the ultrasound power, temperature, type of alcohol, and alcohol/biodiesel molar ratio. Trimethylene glycol produced 90 ± 1.9% of biolubricant at 80 °C and 62 W with a molar ratio of 0.25. Calcium oxide supported on silica (CaO/SiO2) also catalyzed the reaction under optimal conditions. The yield of the CaO/SiO2-catalyzed reaction was two times lower than that obtained with NaOH. We surveyed the loading of CaO over SiO2, the catalyst loading in the reactor, and its leaching and reusability. A mass percentage of 50% CaO to SiO2 yielded 46 ± 3.2% lubricants at 3% by weight of the reactants’ total mass. After three reaction cycles, the ultrasound did not alter the particle size (e.g., mean diameters of fresh and used catalysts were 31 and 32 μm, respectively), but it leached the active sites, which reduced the activity of the catalyst for successive uses