Alkylphosphonic acid- and small amine-templated synthesis of hierarchical silicoaluminophosphate molecular sieves with high isomerization selectivity to di-branched paraffins

2012 ◽  
Vol 285 (1) ◽  
pp. 251-259 ◽  
Author(s):  
Yu Fan ◽  
Han Xiao ◽  
Gang Shi ◽  
Haiyan Liu ◽  
Xiaojun Bao
Keyword(s):  
Molecular Sieves ◽  
Templated Synthesis ◽  
Isomerization Selectivity ◽  
Alkylphosphonic Acid

scholarly journals Toward Understanding of the Effect of Nucleation Temperature on Porous Structure of Micro-Mesoporous Composite Molecular Sieves and Related Crystallization Mechanism

Catalysts ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 777 ◽  
Author(s):  
Chunwei Shi ◽  
Jingjing Liu ◽  
Wenyuan Wu ◽  
Xue Bian ◽  
Ping Chen ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Porous Structure ◽  
Molecular Sieves ◽  
Crystallization Mechanism ◽  
Nucleation Temperature ◽  
X Ray Diffraction ◽  
Mesoporous Composite ◽  
Transmission Electron ◽  
Isomerization Selectivity ◽  
Crystal Particle

Although micro-mesoporous composite molecular sieves have received significant attention due to their desirable properties, they still lack systematic studies on their crystallization process to achieve controllable synthesis of composite molecular sieves. In this study, a series of Y/SBA-15 micro-mesoporous composite molecular sieves with different porous structures were synthesized by tuning nucleation temperature, based on epitaxial growth on the outer surface of the Y-type crystal particle. All composite molecular sieves were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM). Moreover, the effect of nucleation temperature on the structure of composite molecular sieves was investigated, while the crystallization mechanism was also explored. Furthermore, the performance of the molecular sieves on isomerization of n-pentane was investigated, the results suggested that the isomerization selectivity was positively correlated with regularity degree of the mesoporous porous structure, where the highest isomerization reached 95.81%. This work suggests that nucleation temperature plays a key role in structures of micro-mesoporous composite molecular sieves, providing a solid basis for the further development of functional composite molecular sieves.

Synthesis of Four Monodimensional Medium-Pore Zeolites and their Hydroisomerization Performances of n-Dodecane

2011 ◽  
Vol 236-238 ◽  
pp. 854-857 ◽  
Author(s):  
Jun Liang ◽  
Fu Ping Wang
Keyword(s):  
Hydrothermal Method ◽  
Molecular Sieves ◽  
Acid Sites ◽  
Acid Strength ◽  
Channel Structure ◽  
Pore Channel ◽  
Catalytic Materials ◽  
Isomerization Selectivity

SAPO-11, SAPO-41, ZSM-22, ZSM-12 were synthesized by the hydrothermal method and characterized by XRD, SEM and NH3-TPD. Effects of pore channel, the number of acid sites and acid strength on hydroisomerization ofn-dodecane were examined over Pt-loaded corresponding zeolites. The results indicate that the selectivity to isomers in hydroisomerization ofn-dodecane is highly influenced by channel structure in zeolites and the conversion activity ofn-dodecane is dependent on acidity of zeolites. Monodimensional ten-ring molecular sieves are ideal catalytic materials for higher isomerization selectivity in hydroisomerization ofn-dodecane regardless of acid strength, such as SAPO-11, SAPO-41 and ZSM-22.

In vitro assembly of 2-D crystals from partially purified EA1 protein secreted by Bacillus anthracis strain Delta Sterne-1

1994 ◽  
Vol 52 ◽  
pp. 276-277
Author(s):  
Mary Beth Downs ◽  
Wilson Ribot ◽  
Joseph W. Farchaus
Keyword(s):  
Cell Wall ◽  
Molecular Sieves ◽  
Cell Envelope ◽  
Single Species ◽  
Supporting Cell ◽  
Surface Layers ◽  
Rabbit Igg ◽  
In Vitro Assembly ◽  
Covalently Linked

Many bacteria possess surface layers (S-layers) that consist of a two-dimensional protein lattice external to the cell envelope. These S-layer arrays are usually composed of a single species of protein or glycoprotein and are not covalently linked to the underlying cell wall. When removed from the cell, S-layer proteins often reassemble into a lattice identical to that found on the cell, even without supporting cell wall fragments. S-layers exist at the interface between the cell and its environment and probably serve as molecular sieves that exclude destructive macromolecules while allowing passage of small nutrients and secreted proteins. Some S-layers are refractory to ingestion by macrophages and, generally, bacteria are more virulent when S-layers are present.When grown in rich medium under aerobic conditions, B. anthracis strain Delta Sterne-1 secretes large amounts of a proteinaceous extractable antigen 1 (EA1) into the growth medium. Immunocytochemistry with rabbit polyclonal anti-EAl antibody made against the secreted protein and gold-conjugated goat anti-rabbit IgG showed that EAI was localized at the cell surface (fig 1), which suggests its role as an S-layer protein.

Substrate templated synthesis of single-phase and uniform Zr-porphyrin-based metal–organic frameworks

2020 ◽  
Vol 7 (1) ◽  
pp. 221-231
Author(s):  
Seong Won Hong ◽  
Ju Won Paik ◽  
Dongju Seo ◽  
Jae-Min Oh ◽  
Young Kyu Jeong ◽  
...  
Keyword(s):  
Chemical Bath Deposition ◽  
Single Phase ◽  
Metal Organic Frameworks ◽  
Templated Synthesis ◽  
Pore Structures ◽  
Phase Pure ◽  
Metal Organic ◽  
Cbd Method

We successfully demonstrate that the chemical bath deposition (CBD) method is a versatile method for synthesizing phase-pure and uniform MOFs by controlling their nucleation stages and pore structures.

Rapid, Non-Toxic Synthesis of Beta Zeolites

2018 ◽  
Author(s):  
Felix Hemmann ◽  
Jonathan Hackebeil ◽  
Andreas Lißner ◽  
Florian Mertens
Keyword(s):  
Hydrofluoric Acid ◽  
Molecular Sieves ◽  
Toxic Chemicals ◽  
Lewis Acidity ◽  
Beta Zeolite ◽  
Seeded Growth ◽  
Related Research ◽  
Beta Zeolites ◽  
Growth Method ◽  
Fast Synthesis

Molecular sieves with beta zeolite topology are promising catalysts for various reactions as they exhibits extraordinary Lewis acidity. However, their industrial application and related research in academica is hindered because their synthesis is time consuming and typically involves toxic chemicals as hydrofluoric acid. Therefore, tetraethylammonium fluorid was tested as a non-toxic fluotide source for the synthesis of beta zeolites. In combination with the previously reported nano-seeded growth method, a fast synthesis of beta zeolites only involving non-toxic chemicals was possible. Synthesized zeolites show comparable selectivity in the Bayer-Villinger oxidation as conventional zeolites synthesized with hydrofluoric acid.<br>

CHARACTERISATION OF ETS-10 AND ET(Fe)S-10 MOLECULAR SIEVES EXCHANGED WITH DIFFERENT CATIONS

2004 ◽  
Vol 3 (3) ◽  
pp. 231-238
Author(s):  
Pierantonio De Luca ◽  
Lucia Catanzaro ◽  
Danilo Vuono ◽  
Janos B. Nagy ◽  
Alfonso Nastro
Keyword(s):  
Molecular Sieves
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