A5027944064- Zeolite Catalysis and Synthesis
- Mesoporous Materials and Catalysis
- Catalytic Processes in Materials Science
- Chemical Synthesis and Characterization
- Metal-Organic Frameworks: Synthesis and Applications
- Catalysis and Hydrodesulfurization Studies
- Catalysis and Oxidation Reactions
- Gas Sensing Nanomaterials and Sensors
- Nanomaterials for catalytic reactions
- Analytical Chemistry and Sensors
- Glass properties and applications
- Photorefractive and Nonlinear Optics
- Advanced NMR Techniques and Applications
- Membrane Separation and Gas Transport
- Photonic and Optical Devices
- Covalent Organic Framework Applications
- Advanced Photocatalysis Techniques
- Catalysis for Biomass Conversion
- Polyoxometalates: Synthesis and Applications
- Advanced Chemical Sensor Technologies
- Nanoparticle-Based Drug Delivery
- Carbon Dioxide Capture Technologies
- Membrane Separation Technologies
- Inorganic and Organometallic Chemistry
- Lubricants and Their Additives
Centre National de la Recherche Scientifique
2016-2025
Laboratoire Catalyse et Spectrochimie
2016-2025
Université de Caen Normandie
2016-2025
École Nationale Supérieure d'Ingénieurs de Caen
2016-2025
China University of Petroleum, East China
2018-2025
State Key Laboratory of Heavy Oil
2025
Normandie Université
2016-2024
China National Petroleum Corporation (China)
2020-2023
Total (Belgium)
2023
China University of Petroleum, Beijing
2018-2022
The formation and growth of crystal nuclei zeolite A from clear solutions at room temperature were studied with low-dose, high-resolution transmission electron microscopy in field emission mode situ dynamic light scattering. Single crystals nucleated amorphous gel particles 40 to 80 nanometers within 3 days temperature. resulting nanoscale single (10 30 nanometers) embedded the particles. consumed during further temperature, forming a colloidal suspension nanocrystals nanometers. On heating...
This review highlights recent developments in the synthesis of nanosized zeolites. The strategies available for their preparation (organic-template assisted, organic-template free, and alternative procedures) are discussed. Major breakthroughs achieved by so-called zeolite crystal engineering encompass items such as mastering using physicochemical properties precursor gel/suspension, optimizing use silicon aluminium sources, rational organic templates structure-directing inorganic cations,...
This article covers the recent development in remarkably growing field of synthesis, characterization and particularly catalytic investigation zeolite‐based materials combining micro‐ mesoporous features. New synthetic approaches for preparation micro/mesoporous composites including recrystallization originally amorphous matter, utilization nanocrystalline zeolite seeds formation single crystals are first focus this article. The advantages disadvantages composite comparison with pure...
Controlling Zeolite Nucleation Small zeolite crystals are of increasing interest as catalysts and for membrane separations because they allow the high selectivity their cages to be exploited while minimizing kinetic limitations caused by diffusion. Ng et al. (p. 70 , published online 8 December) synthesized ultrasmall (6 15 nanometers) EMT zeolite, which has a low framework density good catalytic properties hydrocarbon “cracking” (conversion large smaller ones). The synthesis normally...
The localization of hydrogen atoms is an essential part crystal structure analysis, but it difficult because their small scattering power. We report the direct in nanocrystalline materials, achieved using recently developed approach dynamical refinement precession electron diffraction tomography data. used this method to locate both organic (paracetamol) and inorganic (framework cobalt aluminophosphate) material. results demonstrate that technique can reliably reveal fine structural details,...
This paper will review the crystal growth mechanism of zeolites and discuss some latest findings in this field. A great effort has been dedicated recent years to improving fundamental understanding zeolite during synthesis process, with overall aim increasing control over properties structure. The studies on crystallization colloidal (clear) suspensions, prepared by addition organic inorganic structural directing agents, comparison traditional gel seed-approach be discussed. Further...
Abstract The preparation of hierarchical zeolites with reduced diffusion limitation and enhanced catalyst efficiency has become a vital focus in the field porous materials chemistry within past decades. This review will on industrial catalysts. benefits at two levels hierarchies (zeolitic component level level) from chemical reaction engineering point view be analysed. At zeolitic level, three types mesopores based strategies applied toward enhancing effectiveness factor are presented: (i)...
ZSM-5 nanocrystals were synthesized from organic-template-free gel systems containing 0.1, 1.0, and 3.0 wt % of 80 nm silicalite-1 seeds. The syntheses performed at 100, 120, 150, 170 °C for periods time ranging between 3 190 h. Physicochemical characteristics derived XRD, NMR, TG/DTA, SEM/TEM, DLS, N2 adsorption chemical analyses Na-ZSM-5 compared with those the nanosized tetrapropylammonium (TPA)-promoted counterpart. Crystalline yield colloidal stability materials obtained under different...
The growth of nanoscale crystals zeolite Y from colloidal aluminosilicate gel particles has been investigated with high-resolution electron microscopy. Each amorphous particle nucleates only a single crystal, nucleation beginning at the gel-solution interface (see scheme). Further these nanocrystals is possible through solution-mediated transport framework building blocks.
Low- and no-template precursor suspensions are studied to clarify the effects of Si/Al ratio, seed content, heating temperature, crystallization time on syntheses Al-rich zeolite Beta. Syntheses using 2.5 wt % seeds resulted in well-shaped octahedral Beta crystals with sizes between 0.4 1 μm after either 6 days hydrothermal treatment at 125 °C or 12 100 °C. The crystalline product has ratios as low 3.9 (16.4 Al atoms per unit cell), which comparable natural counterpart Beta, mineral...
Zeolites are widely used in industrial processes, mostly as catalysts or adsorbents. Increasing their micropore volume could further improve already exceptional catalytic and separation performances. We report a tunable extraction of zeolite framework cations (Si, Al) on faujasite-type zeolite, the archetype molecular sieves with cages most catalyst sorbent; this results ca. 10% higher limited impact its thermal stability. This increased from opening some small (sodalite) cages, otherwise...
The fluid catalytic cracking (FCC) technology is one of the pillars modern petroleum industry which converts crude oil fractions into many commodity fuels and platform chemicals, such as gasoline. Although FCC field quite mature, research scope still enormous due to changing feedstock, gradual shifts in market demands evolved unit operations. In this review, we have described current status technology, variation present day feedstocks catalysts, particularly, great attention paid effects...
Abstract Zeolites are widely used in many commercial processes, mostly as catalysts or adsorbents. Understanding their intimate structure at the nanoscale is key to control properties and design best materials for ever increasing uses. Herein, we report a new controllable fluoride treatment non‐discriminate extraction of zeolite framework cations. This sheds light on sub‐structure commercially relevant crystals: they segmented along defect zones exposing numerous nanometer‐sized crystalline...
This feature article highlights recent developments in nanosized zeolites and addresses the question: what will be next? Until recently limiting step to practical applications was determined by challenging synthesis of high yield adequate form. The advances nanozeolites that provide basis for future diverse are reviewed. main trends challenges processing, characterization summarized. Particular attention is paid processing terms their further use. extending nanotechnology, medicine,...
Abstract Green and efficient synthesis of titanium‐containing molecular sieves is limited by the quantity environmentally unfriendly additives complicated procedures required. Oligomerization Ti monomers into anatase TiO 2 typical outcome such because a mismatch between hydrolysis rates Si precursors. We report simple generic additive‐free route for Ti‐containing (MFI, MEL, BEA). This approach successfully reverses formation oligomers to match species with assistance hydroxyl free radicals...
Abstract Small‐pore zeolites such as chabazite (CHA) are excellent candidates for the selective separation of CO 2 ; however, current synthesis involves several steps and use organic structure‐directing agent (OSDA), increasing their cost energy requirements. We report small‐pore zeolite crystals (aluminosilicate) with CHA‐type framework structure by direct in a colloidal suspension containing mixture inorganic cations only (Na + , K Cs ). The location molecules host was revealed 3D electron...