A Zeolite-Templated Carbon Synthesized from Extralarge-Pore Zeolite ZEO-1.

A new member of the zeolite-templated carbon (ZTC) family with unprecedented properties has been developed using extralarge-pore zeolite ZEO-1 (JZO) as a template. The resulting ZTC-JZO exhibits strong X-ray diffraction long-range order, replicating three distinct zeolite planes with different lattice spacings. By harnessing the enhanced micropore void volume in the ZEO-1 template, we achieved the first ZTC with a bimodal micropore size distribution, resulting in superior skeleton density and thickness.

Acidity: A Key Parameter in Zeolite-Templated Carbon Formation.

This work reveals the crucial role of zeolite acidity in the synthesis of zeolite-templated carbons (ZTCs). While textural and chemical properties appear to be independent from acidity at a given synthesis temperature, the spin concentration in hybrid materials appears to be strongly impacted by the zeolite acid site concentration. The electrical conductivity of the hybrids and resulting ZTCs are closely related to the spin concentration in the hybrid materials.

Can We Form Mesoporous Zeolites by Steam Assisted Crystallization of MCM-41?

The possibility of crystallizing silicalite-1 (MFI) from the pore walls of as-synthesized MCM-41 via steam-assisted crystallization (SAC) was thoroughly investigated. A kinetic study was conducted through the impregnation of as-synthesized MCM-41 with the structure-directing agent tetrapropyl-ammonium hydroxide (TPAOH). Materials obtained after different SAC treatment times (1−288 h) were characterized by XRD, nitrogen physisorption at 77 K, TGA/DTA, and SEM.

Gas Porosimetry by Gas Adsorption as an Efficient Tool for the Assessment of the Shaping Effect in Commercial Zeolites.

A set of three commercial zeolites (13X, 5A, and 4A) of two distinct shapes have been characterized: (i) pure zeolite powders and (ii) extruded spherical beads composed of pure zeolite powders and an unknown amount of binder used during their preparation process. The coupling of gas porosimetry experiments using argon at 87 K and CO at 273 K allowed determining both the amount of the binder and its effect on adsorption properties. It was evidenced that the beads contain approximately 25 wt% of binder.

The Energetics of Surfactant-Templating of Zeolites.

Mesoporosity can be conveniently introduced into zeolites by treating them in basic surfactant solutions. The apparent activation energy involved in the formation of mesopores in USY by surfactant-templating was determined using a combination of in situ synchrotron X-ray diffraction and ex situ gas adsorption. Additionally, techniques such as pH measurement and thermogravimetry/differential thermal analysis were employed to determine OH evolution and cetyltrimethylammonium ion (CTA ) uptake during the development of mesoporosity, thereby providing information about the different steps involved.

Indocyanine green-assisted sentinel lymph node biopsy in melanoma using the "FOVIS" system.

Background: Metastatic involvement of the sentinel lymph node (SLN) represents a key prognostic factor in melanoma. The combined use of a radiocolloid (technetium-99m) and blue dye is the gold standard in sentinel lymph node biopsy (SLNB). In this context, near-infrared (NIR) fluorescence imaging with indocyanine green (ICG) has been suggested as an alternative.

Sentinel-Lymphknoten-Biopsie des Melanoms mittels Indocyaningrün und "FOVIS"-System.

Hintergrund: Der Nachweis metastatischer Infiltrate im Sentinel-Lymphkoten (SLN) gilt als wesentlicher prognostischer Faktor des Melanoms. Alternativ zur Farbstoffmethode mit Patentblau zum Goldstandard der SLN-Biopsie (SLNB) mittels Radiokolloid wird die fluoreszenzoptische Darstellung mit Hilfe von Indocyaningrün (ICG) und Nahinfrarot (NIR)-Kamerasystem kommuniziert. Im Vergleich zur konventionellen Methode wurde die Wertigkeit des ICG-/NIR-Verfahrens in Abhängigkeit vom Body-Mass-Index (BMI) des Patienten und der Konzentration von ICG bezüglich der Visualisierung des Lymphabstroms und des SLNs untersucht.

Mesoporous alumina from colloidal biotemplating of Al clusters.

A simple and green synthesis route was disclosed for the achievement of mesoporous alumina microparticles employing polysaccharide nanoparticles (α-chitin nanorods) as templates. Pore textures can be tuned by the cationic alumina precursor. Compared to small cations, the use of Al13 and Al30 oxo-hydroxo clusters leads to better defined and elongated mesopores.

Ordered mesoporous ZSM-5 employing an imidazolium-based ionic liquid.

Hierarchically porous ZSM-5 was achieved by using a simple bottom-up strategy combining zeolite seeds with imidazolium-based ionic liquids. The bimodal ZSM-5 with hexagonal arranged mesopores (3 nm) shows important activity in the acid catalysis of bulky compounds relative to conventional ZSM-5.

Selective hydrogenation over Pd nanoparticles supported on a pore-flow-through silica monolith microreactor with hierarchical porosity.

Well-dispersed Pd nanoparticles have been synthesized inside the mesoporosity of a silica monolith featuring hierarchical porosity of homogeneous interconnected macropores (4 microns) and mesopores (11 nm). These monoliths have been implemented as microreactors for selective hydrogenation reactions. Conversion and selectivity can be tuned by adjusting the flow rates of hydrogen and substrates.

In situ synthesis of Cu-BTC (HKUST-1) in macro-/mesoporous silica monoliths for continuous flow catalysis.

The metal-organic framework Cu-BTC has been successfully synthesized as nanoparticles inside the mesopores of silica monoliths featuring a homogeneous macropore network enabling the use of Cu-BTC for continuous flow applications in liquid phase with low pressure drop. High productivity was reached with this catalyst for the Friedländer reaction.

Challenges and Strategies in the Synthesis of Mesoporous Alumina Powders and Hierarchical Alumina Monoliths.

A new rapid, very simple and one-step sol-gel strategy for the large-scale preparation of highly porous γ-Al₂O₃ is presented. The resulting mesoporous alumina materials feature high surface areas (400 m² g), large pore volumes (0.8 mL g) and the γ-Al₂O₃ phase is obtained at low temperature (500 °C).

Functionalized inorganic monolithic microreactors for high productivity in fine chemicals catalytic synthesis.

Highly productive: Grafted monolith silica skeleton microreactors process bulky molecules more efficiently than a batch mode reactor. This efficiency is due to a higher contact area, shorter diffusion path, and lower inhibition by products in the thin monolith skeleton. These materials provide a new approach in the field of heterogeneous catalysis for the synthesis of fine chemicals.