Lanthanide-Based Metal Organic Frameworks: Synthetic Strategies and Catalytic Applications

SSCI-VIDE+ING+CPGInternational audienceThis short critical review outlines the main synthetic strategies used in the designed synthesis of lanthanide-based metal organic frameworks (Ln-MOFs). It explains the impact of the choice of organic linker on the final network topology, and it highlights the applications of Ln-MOFs in the catalysis of organic reactions

Lanthanide-Based Metal Organic Frameworks: Synthetic Strategies and Catalytic Applications

SSCI-VIDE+ING+CPGInternational audienceThis short critical review outlines the main synthetic strategies used in the designed synthesis of lanthanide-based metal organic frameworks (Ln-MOFs). It explains the impact of the choice of organic linker on the final network topology, and it highlights the applications of Ln-MOFs in the catalysis of organic reactions

Synthesis of hollow Y zeolite for catalytic applications

SSCI-VIDE+ING+CPG:DFA:ATUInternational audienceMainly motivated by catalytic applications, the design of zeolites with diverse and well controlled morphologies remains a topic of intense research and development. In this sense, it is worth highlighting FAU-type materials that are extensively used in industrial catalytic and adsorption processes. The design of multimodal pore Y zeolite materials have been then emerging in order to combine the catalytic features of the zeolite and improved transport properties. In the literature, we can distinguish between two different approachesfor multimodal pore systems: creation of hierarchical structures with intraparticle mesopores and synthesis of nanocrystals (< 100 nm) with interparticle mesopores. Both approaches yield Y zeolite materials with smaller zeolite domains and concomitant larger external surface area.Here, we propose an alternative approach that consists in synthesizing a new class of crystalline materials: hollow Y zeolite crystals which possess a large central cavity and similar size and shape to the parent crystals. In contrast to classical hierarchical zeolite materials, following this procedure, it can be obtained a smaller zeolite domain, i.e. the walls are thinner while the external surface remains approximatively the same. So far,hollow single crystals have mainly been created from MFI-type zeolites thanks to a natural gradient of composition. The dissolution/recrystallization approach cannot be directly applied to as-synthesized Y zeolites, because the homogeneous distribution of aluminum throughout the crystals prevents a preferential dissolution of the core as opposed to the surface.We report for the first time, a top-down pathway for the synthesis of original hollow Y zeolite from parent crystals in which a gradient of composition has been artificially created. Materials were obtained by a three-step process based on successive dealumination/realumination reactions followed by a selective dissolution of crystal cores.See this article for further informations : Pagis et al., CrystEngComm, 2018, 20, 1564 - 157

Synthesis of hollow Y zeolite for catalytic applications

SSCI-VIDE+ING+CPG:ATU:DFAInternational audienceHighly crystalline hollow Y zeolite capsules have been obtained for the first time. Starting from clas-sical NaY, the three-step process involves the formation of an artificial composition gradient within the crystals followed by a selective dissolution of crystal cores. Hollow Y zeolite crystals contain a single large internal cavity, a wall thickness of about 0.15 μm and an overall size similar to that of the starting materials. The well-defined Y zeolite capsules provide an alternative design to hierar-chical and nanosized zeolites for adsorption and catalysis. They shall offer fastest transport compared to the bulk due to the thin walls. Moreover, the effect of hollow structures on mass transport by transient adsorption methods (TAP measurements) and catalytic tests (hydrogenation of alkenes) will be reported in the basis of Thiele modulus and effectiveness factor studies

Synthesis of hollow Y zeolite for catalytic applications

SSCI-VIDE+ING+CPG:DFA:ATUInternational audienceMainly motivated by catalytic applications, the design of zeolites with diverse and well controlled morphologies remains a topic of intense research and development. In this sense, it is worth highlighting FAU-type materials that are extensively used in industrial catalytic and adsorption processes. The design of multimodal pore Y zeolite materials have been then emerging in order to combine the catalytic features of the zeolite and improved transport properties. In the literature, we can distinguish between two different approachesfor multimodal pore systems: creation of hierarchical structures with intraparticle mesopores and synthesis of nanocrystals (< 100 nm) with interparticle mesopores. Both approaches yield Y zeolite materials with smaller zeolite domains and concomitant larger external surface area.Here, we propose an alternative approach that consists in synthesizing a new class of crystalline materials: hollow Y zeolite crystals which possess a large central cavity and similar size and shape to the parent crystals. In contrast to classical hierarchical zeolite materials, following this procedure, it can be obtained a smaller zeolite domain, i.e. the walls are thinner while the external surface remains approximatively the same. So far,hollow single crystals have mainly been created from MFI-type zeolites thanks to a natural gradient of composition. The dissolution/recrystallization approach cannot be directly applied to as-synthesized Y zeolites, because the homogeneous distribution of aluminum throughout the crystals prevents a preferential dissolution of the core as opposed to the surface.We report for the first time, a top-down pathway for the synthesis of original hollow Y zeolite from parent crystals in which a gradient of composition has been artificially created. Materials were obtained by a three-step process based on successive dealumination/realumination reactions followed by a selective dissolution of crystal cores.See this article for further informations : Pagis et al., CrystEngComm, 2018, 20, 1564 - 157

Hollow Zeolite Structures: An Overview of Synthesis Methods

SSCI-VIDE+ING+CPG:DFA:ATUInternational audienceHollow capsules with dimensions below 1 mu m have recently attracted much attention due to their potential applications as catalysts as well as biomedical and pharmaceutical vectors for controlled drug delivery. Among them, hollow zeolites are particularly interesting because they possess (0 a crystalline structure, which greatly improves their hydrothermal and chemical stability as compared to amorphous silica analogs and (ii) a microporous network that acts as a shape-selective membrane. Moreover, their properties can be continuously tuned by changing their composition, in particular the framework aluminum content. In this perspective review, we examine the recent progress in the development of synthetic methods for the preparation of hollow zeolite and zeotype structures, from templating routes providing large polycrystalline capsules to controlled dissolution methods leading to nanometer-sized hollow single crystals. The applications of these materials will be illustrated and discussed, namely their main potential as catalytic nanoreactors, these being materials particularly adapted for the encapsulation and the confinement of metal nanoparticles. Critical perspectives on future materials with specific properties are also addressed, particularly those with less common zeolite structures and/or compositions

Hollow structures by controlled desilication of beta zeolite nanocrystals

MICROSCOPIE+ING+LBU:DFA:ATUInternational audienceBeta zeolit

Bismuth Oxyfluoride Compounds as Emerging Photocatalytic Materials: from powder to thin films.

International audienc

Bismuth oxyfluoride compounds as emerging photocatalytic materials: from powders to thin films.

International audienc