Extraframework sodium cation sites in sodium zeolite Y probed by sodium-23 double-rotation NMR

1992 ◽  
Vol 114 (12) ◽  
pp. 4907-4908 ◽  
Author(s):  
Raz Jelinek ◽  
Saim Ozkar ◽  
Geoffrey A. Ozin
Keyword(s):  
Zeolite Y ◽  
Sodium Cation ◽  
Cation Sites

ChemInform Abstract: Extraframework Sodium Cation Sites in Sodium Zeolite Y Probed by 23Na Double-Rotation NMR.

ChemInform ◽  
2010 ◽  
Vol 23 (36) ◽  
pp. no-no
Author(s):  
R. JELINEK ◽  
S. OEZKAR ◽  
G. A. OZIN
Keyword(s):  
Zeolite Y ◽  
Sodium Cation ◽  
Cation Sites

Probing Cation Sites in Cesium-Exchanged Zeolite Y via133Cs MAS NMR

1996 ◽  
Vol 100 (41) ◽  
pp. 16662-16666 ◽  
Author(s):  
Andrzej Malek ◽  
Geoffrey A. Ozin ◽  
Peter M. Macdonald
Keyword(s):  
Zeolite Y ◽  
Mas Nmr ◽  
Cation Sites

Raman spectra of pyridine adsorbed on a series of ion-exchanged forms of zeolite Y

1976 ◽  
Vol 54 (4) ◽  
pp. 586-598 ◽  
Author(s):  
T. A. Egerton ◽  
A. H. Hardin ◽  
N. Sheppard
Keyword(s):  
Raman Spectra ◽  
Zeolite Y ◽  
Raman Band ◽  
Unsaturated Hydrocarbon ◽  
Nay Zeolite ◽  
Y Zeolite ◽  
Hy Zeolite ◽  
Oh Groups ◽  
Oxygen Treatment ◽  
Cation Sites

As with other silicas and aluminas, it is shown that a broad general fluorescence from Y zeolite samples excited by irradiation with the 6328 Å line of a He/Ne laser can be greatly reduced by heating the zeolite in oxygen at 500 °C. This general fluorescence is attributed to the presence of traces of unsaturated hydrocarbon impurities which can be burned off by the oxygen treatment. A narrower residual fluorescence in the region of 14 000–14 500 cm−1 is attributed to the presence of Fe3+ impurities.Successful Raman spectra using He–Ne laser excitation have been obtained from pyridine adsorbed on oxygen-treated NaY zeolite, and on samples of this zeolite in which the majority of sodium ions have been replaced by Li+, K+, Co2+, Cu2+, Ce3+ or H+ (decationated Y zeolite). The position of the v1 Raman band from the ring-breathing mode of pyridine is found to give a linear correlation with q/r for the metal ions (where q is the charge and r the radius of an ion) strongly suggesting that the main adsorption is at cation sites. During adsorption of pyridine on CeY the spectrum changes as a function of time. Adsorption on Ce3+ appears to be the final situation and intermediate Raman spectra suggest that pyridine adsorbs and forms hydrogen bonds with surface OH groups; quite different Raman spectra are obtained from these two surface species. The Raman spectra of pyridine on HY zeolite is consistent with the coexistence of pyridinium ions and hydrogen-bonded pyridine molecules.

Site occupancy in gamma alumina

1996 ◽  
Vol 54 ◽  
pp. 654-655
Author(s):  
C. A. Bateman ◽  
A.Z. Ringwelski ◽  
R.W. Broach
Keyword(s):  
Spinel Structure ◽  
Site Occupancy ◽  
Unit Cell ◽  
Neutron Diffraction Data ◽  
Gamma Alumina ◽  
Tetrahedral Sites ◽  
Powder Neutron Diffraction ◽  
Cation Sites ◽  
Powder Neutron Diffraction Data ◽  
Insufficient Number

Gamma (γ) alumina is referred to as a defect spinel because it has a tetragonally distorted spinel structure (AB2O4) and an insufficient number of cations to fill all cation sites. In the spinel structure, the oxygen lattice is cubic close packed with A- and B-site cations in tetrahedral and octahedral coordination, respectively. The 2l⅓ Al atoms per unit cell of γ alumina can distribute themselves across 16 octahedral and 8 tetrahedral sites.The literature differs on where the 2⅔ cation vacancies per unit cell are located. Wilson and McConnell proposed that the vacancies in γ alumina, as first formed by calcining boehmite, are predominantly on the tetrahedral lattice but, with further heat treatment, move to occupy random positions on both octahedral and tetrahedral lattices. One study using NMR showed that the vacancies lay exclusively on the tetrahedral lattice, independent of the calcination temperature. A more-recent study using Rietveld refinement of powder neutron diffraction data suggested that both octahedral and tetrahedral lattices were partially occupied.

Surface roughness measurements of vanadium-contaminated fluidized cracking catalysts by atomic force microscopy

1996 ◽  
Vol 54 ◽  
pp. 866-867
Author(s):  
H. Kinney ◽  
M.L. Occelli ◽  
S.A.C. Gould
Keyword(s):  
Surface Roughness ◽  
Zeolite Y ◽  
Atomic Level ◽  
Microporous Structure ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
Roughness Measurements ◽  
Cracking Catalysts

For this study we have used a contact mode atomic force microscope (AFM) to study to topography of fluidized cracking catalysts (FCC), before and after contamination with 5% vanadium. We selected the AFM because of its ability to well characterize the surface roughness of materials down to the atomic level. It is believed that the cracking in the FCCs occurs mainly on the catalysts top 10-15 μm suggesting that the surface corrugation could play a key role in the FCCs microactivity properties. To test this hypothesis, we chose vanadium as a contaminate because this metal is capable of irreversibly destroying the FCC crystallinity as well as it microporous structure. In addition, we wanted to examine the extent to which steaming affects the vanadium contaminated FCC. Using the AFM, we measured the surface roughness of FCCs, before and after contamination and after steaming.We obtained our FCC (GRZ-1) from Davison. The FCC is generated so that it contains and estimated 35% rare earth exchaged zeolite Y, 50% kaolin and 15% binder.

SO3H-functionalized Zeolite-Y as an Efficient Nanocatalyst for the Synthesis of Nbenzimidazole- 2-aryl-4-thiazolidinones and tri-substituted Imidazoles

2020 ◽  
Vol 17 (2) ◽  
pp. 117-130 ◽  
Author(s):  
Mehdi Kalhor ◽  
Zohre Zarnegar ◽  
Zahra Seyedzade ◽  
Soodabeh Banibairami
Keyword(s):  
Zeolite Y ◽  
Internal Standard ◽  
Acid Catalyst ◽  
Aromatic Aldehydes ◽  
Reaction Rates ◽  
Ambient Conditions ◽  
Catalytic Method ◽  
Efficient Catalyst ◽  
Bet Analysis ◽  
Ft Ir

Background: SO3H-functionalized zeolite-Y was prepared and used as a catalyst for the synthesis of 2-aryl-N-benzimidazole-4-thiazolidinones and tri-substituted imidazoles at ambient conditions. Objective: The goals of this catalytic method include excellent yields and high purity, inexpensive procedure and ease of product isolation, the use of nontoxic and heterogeneous acid catalyst, shorter reaction times and milder conditions. Materials and Methods: NMR spectra were recorded on Brucker spectrophotometer using Me4Si as internal standard. Mass spectra were recorded on an Agilent Technology 5975C VL MSD with tripe-axis detector. FTIR spectra were obtained with KBr disc on a galaxy series FT-IR 5000 spectrometer. The surface morphology of nanostructures was analyzed by FE-SEM (EVO LS 10, Zeiss, Carl Zeiss, Germany). BET analysis were measured at 196 °C by a Japan Belsorb II system after the samples were vacuum dried at 150°C overnight. Results: The NSZ was characterized by FT-IR, FESEM, EDX, XRF, and BET. The catalytic activity of NSZ was investigated for synthesis of 1,3-tiazolidin-4-ones in H2O/Acetone at room temperature. Moreover, NSZ was used for synthesis of tri-substituted imidazoles at 60 °C via solvent-free condensation. Different kinds of aromatic aldehydes were converted to the corresponding of products with good to excellent yields. Conclusion: Sulfonated zeolite-Y was as an efficient catalyst for the preparation of N-benzimidazole-2-aryl-1,3- thiazolidin-4-ones and 2,4,5-triaryl-1H-imidazoles. High reaction rates, elimination toxic solvent, simple experimental procedure and reusability of the catalyst are the important features of this protocol.

Flame Photometry Characterization Procedure for Sodium Content in Brazilian Bentonites for Nanotechnology Applications

2019 ◽  
Vol 12 (2) ◽  
pp. 122-129
Author(s):  
Hellen S. Santos ◽  
Karine L. Buarque da Silva ◽  
Ariel E. Zanini ◽  
Danilo S. Coelho ◽  
Marcelo Embiruçu ◽  
...  
Keyword(s):  
Control Process ◽  
Sodium Concentration ◽  
High Water ◽  
Sodium Content ◽  
Industrial Applications ◽  
Exchange Capacity ◽  
Sodium Cation ◽  
Flame Photometry ◽  
Logarithmic Scale ◽  
Average Value

Background: Brazilian bentonites have a low sodium concentration in their interlayer structure. This is a problem with most of the industrial applications that demand the characteristics of sodium bentonites. Objective: As a solution for this limitation, sodium carbonate is added to in natura clays, promoting ion exchange between other interlayer cations with sodium. Methods: A process was used based on the principle of Stokes’ Law (BR Patent 10 2013 016298). For this, we used four glass columns in series, in which a high water flow was considered to obtain purified clays. It was proposed as a simple, fast and economical method for sodium determination that was developed and applied in bentonites by flame photometry. The equipment calibration was performed with a NaCl standard solution in concentrations between 80 and 110 ppm. The bentonites in the suspension were separated by means of centrifugation, being thus analyzed by a flame photometer. Results: The samples were prepared according to the manufacturer’s specifications to contain detectable amounts of sodium by means of flame photometry. A resulting linear relationship between the average value readings versus sodium standard content solution (both in ppm) was obtained by the logarithmic scale, as expected. Conclusion: The procedure allowed to define a method that could be used in the sodification control process, thus making it possible to differentiate the sodium cation content in terms of the value of cation exchange capacity (CEC) from bentonite. X-ray analysis of in natura and the sodified clays showed nanostructural differences related to interlayer distance.

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