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adsorbed on oxygen-treated NaY zeolite, and on samples of this zeolite in which the majority of sodium ions have been replaced by Li+, K+, Co2+, Cu2+, Ce3+ or H+ (decationated Y zeolite).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.

scholarly journals Surface Chemistry Of Heterobimetallic Ge-M (M = Mo, W) Complexes In Zeolite Y

1991 ◽  
Vol 233 ◽  
Author(s):  
Aticha Borvornwattananont ◽  
Karin Moller ◽  
Thomas Bein
Keyword(s):  
Room Temperature ◽  
Zeolite Y ◽  
In Situ Ftir ◽  
Nay Zeolite ◽  
Zeolite Framework ◽  
Hy Zeolite ◽  
X Ray ◽  
Proton Form ◽  
X Ray Absorption

ABSTRACTThe intrazeolite chemistry of the two germylene complexes Cl2(THF)GeM(CO)5(M = Mo, W) was studied with x-ray absorption spectroscopy (Ge, Mo, W edge EXAFS) and in-situ FTIR/TPD-MS techniques. The slightly decarbonylated GeMo complex interacts with the framework of NaY zeolite at room temperature and retains the Ge-Mo bond up to about 100° C. In proton-loaded HY zeolite, framework interactions increase at elevated temperature, and the attached complex retains the Ge-Mo bond up to about 120° C. The Ge-Mo bond is cleaved at higher temperatures. MoC1x and Mo-Mo species are formed in NaY and HY zeolite, respectively, while GeClx fragments are anchored to the zeolite framework.The complex Cl2 (THF)GeW(CO) 5 retains all five CO ligands up to about 100° C in both NaY and the proton form. Detectable anchoring occurs at room temperature in NaY and at about 80° C in the proton form. WC1x species are formed upon cleavage of the Ge-W bond at higher temperatures.

Activity and regenerability of dealuminated zeolite Y in liquid phase alkylation of benzene with 1-alkene

2010 ◽  
Vol 64 (4) ◽  
Author(s):  
Michal Horňáček ◽  
Pavol Hudec ◽  
Andrej Nociar ◽  
Agáta Smiešková ◽  
Tibor Jakubík
Keyword(s):  
Catalytic Activity ◽  
Liquid Phase ◽  
Hydrochloric Acid ◽  
Zeolite Y ◽  
Batch Reactor ◽  
Selective Extraction ◽  
Y Zeolite ◽  
Hy Zeolite ◽  
Alkylation Of Benzene

AbstractHY-zeolite and its deep-bed dealuminated and EFAL-extracted forms were tested in liquid phase alkylation of benzene with 1-hexadecene in a batch reactor at 120°C. Deep-bed dealumination of the HY-sample at 560 °C followed by careful selective extraction of extra-framework aluminium by hydrochloric acid increased the catalytic activity as well as oxidative regenerability of Y-zeolite.

RAMAN SPECTRA OF TITANIUM DI-, TRI-, AND TETRA-CHLORIDES

2001 ◽  
Vol 15 (28n30) ◽  
pp. 3865-3868 ◽  
Author(s):  
H. MIYAOKA ◽  
T. KUZE ◽  
H. SANO ◽  
H. MORI ◽  
G. MIZUTANI ◽  
...  
Keyword(s):  
Force Constant ◽  
Raman Spectra ◽  
Normal Mode ◽  
Raman Band ◽  
Normal Mode Analysis ◽  
Force Constants ◽  
Mode Analysis ◽  
Oxidation Number

We have obtained the Raman spectra of TiCl n (n= 2, 3, and 4). Assignments of the observed Raman bands were made by a normal mode analysis. The force constants were determined from the observed Raman band frequencies. We have found that the Ti-Cl stretching force constant increases as the oxidation number of the Ti species increases.

scholarly journals Ultra-sound assisted nano Y- zeolite /Mn adsorbent to removed sulfur from crude oil

2021 ◽  
Vol 12 (3) ◽  
pp. 5652-5657
Author(s):  
Dr.Tahseen Hameed khlaif Et. al.
Keyword(s):  
Crude Oil ◽  
Zeolite Y ◽  
Sulfur Compounds ◽  
Ultra Sound ◽  
Adsorption Efficiency ◽  
Y Zeolite ◽  
Industrial Materials ◽  
Oil Sector ◽  
Great Harm ◽  
Adsorbent Dose

There are some types of crude oil that contains large quantities of various sulfur compounds that have great harm on the environment, oil economy, oil sector facilities such as fields and refineries.So developing ways to get rid of it is one of the most important goals of researchers in this sector. In this study, nanotechnology was used for environmentally friendly and available industrial materials (nano-zeolite Y), which can adsorb sulfur from crude oil, especially when it impregnated with manganese metals with ultrasound to increase the adsorption efficiency.  The effect (temperature, adsorbent dose, Samples PH) was studied with ultrasound and without ultrasound.On the efficiency of removal had best results with ultrasound andit was found that this material is highly efficient in removing sulfur compounds, especially at a temperature of 100 C, and at a dose of 13 g, and PH 7 it found the best adsorption efficiency about 99 %. The change in the properties of the adsorbent material is almost non-existent, with a change in the surface area and pore size.

Crystal chemistry of lamprophyllite-group minerals from the Murun alkaline complex (Russia) and pegmatites of Rocky Boy and Gordon Butte (USA): single crystal X-ray diffraction and Raman spectroscopy study

2021 ◽  
Vol 77 (2) ◽  
Author(s):  
Sergey M. Aksenov ◽  
Anastasia D. Ryanskaya ◽  
Yuliya V. Shchapova ◽  
Nikita V. Chukanov ◽  
Nikolay V. Vladykin ◽  
...  
Keyword(s):  
Solid Solution ◽  
Single Crystal ◽  
Raman Spectra ◽  
Crystal Chemistry ◽  
Solid Solution Series ◽  
X Ray Diffraction ◽  
Alkaline Complex ◽  
Oh Groups ◽  
X Ray ◽  
Solution Series

Specific features of the crystal chemistry of lamprophyllite-group minerals (LGMs) are discussed using the available literature data and the results of the single-crystal X-ray diffraction and a Raman spectroscopic studies of several samples taken from the Murun alkaline complex (Russia), and Rocky Boy and Gordon Butte pegmatites (USA) presented here. The studied samples are unique in their chemical features and the distribution of cations over structural sites. In particular, the sample from the Gordon Butte pegmatite is a member of the barytolamprophyllite–emmerichite solid solution series, whereas the samples from the Murun alkaline complex and from the Rocky Boy pegmatite are intermediate members of the solid solution series formed by lamprophyllite and a hypothetical Sr analogue of emmerichite. The predominance of O2− over OH− and F− at the X site is a specific feature of sample Cha-192 from the Murun alkaline complex. New data on the Raman spectra of LGMs obtained in this work show that the wavenumbers of the O—H stretching vibrations depend on the occupancies of the M2 and M3 sites coordinating with (OH)− groups. Cations other than Na+ and Ti4+ (mainly, Mg and Fe3+) can play a significant role in the coordination of the X site occupied by (OH)−. Data on polarized Raman spectra of an oriented sample indicate that the OH groups having different local coordinations have similar orientations with respect to the crystal. The calculated measures of similarity (Δ) for lamprophyllite and ericssonite are identical (0.157 and 0.077 for the 2M- and 2O-polytypes, respectively), which indicates that these minerals are crystal-chemically isotypic and probably should be considered within the same mineral group by analogy to the other mineralogical groups which combine isotypic minerals.

scholarly journals Sustainable Production of Hydrogen by Steam Reforming of Ethanol Using Cobalt Supported on Nanoporous Zeolitic Material

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1934
Author(s):  
Javier Francisco da Costa-Serra ◽  
Maria Teresa Navarro ◽  
Fernando Rey ◽  
Antonio Chica
Keyword(s):  
Steam Reforming ◽  
Zeolite Y ◽  
Cobalt Catalysts ◽  
Coke Deposition ◽  
Bet Surface Area ◽  
Ethanol Conversion ◽  
Y Zeolite ◽  
Steam Reforming Of Ethanol ◽  
Production Of Hydrogen ◽  
Hydrogen Selectivity

Cobalt catalysts supported on Y zeolite and mesoporized Y zeolite (Y-mod) have been studied in steam reforming of ethanol (SRE). Specifically, the effect of the mesoporosity and the acidity of the y zeolite as a support has been explored. Mesoporous were generated on Y zeolite by treatment with NH4F and the acidity was neutralized by Na incorporation. Four cobalt catalysts supported on Y zeolite have been prepared, two using Y zeolite without mesoporous (Co/Y, Co/Y-Na), and two using Y zeolite with mesoporous (Co/Y-mod and Co/Y-mod-Na). All catalysts showed a high activity, with ethanol conversion values close to 100%. The main differences were found in the distribution of the reaction products. Co/Y and Co/Y-mod catalysts showed high selectivity to ethylene and low hydrogen production, which was explained by their high acidity. On the contrary, neutralization of the acid sites could explain the higher hydrogen selectivity and the lower ethylene yields exhibited by the Co/Y-Na and Co/Y-mod-Na. In addition, the physicochemical characterization of these catalysts by XRD, BET surface area, temperature-programmed reduction (TPR), and TEM allowed to connect the presence of mesoporous with the formation of metallic cobalt particles with small size, high dispersion, and with high interaction with the zeolitic support, explaining the high reforming activity exhibited by the co/y-mod-Na sample as well as its higher hydrogen selectivity. It has been also observed that the formation of coke is affected by the presence of mesoporous and acidity. Both properties seem to have an opposite effect on the reforming catalyst, decreasing and increasing the coke deposition, respectively.

Effect of Silver Addition on the Adsorption Properties of Y Zeolite

2020 ◽  
Vol 998 ◽  
pp. 108-113
Author(s):  
Victor L. Temerev ◽  
Aleksey A. Vedyagin ◽  
Kristina N. Iost ◽  
Svetlana V. Cherepanova ◽  
Michael V. Trenikhin
Keyword(s):  
Incipient Wetness Impregnation ◽  
Y Zeolite ◽  
Silver Addition ◽  
Pure Alumina ◽  
Hy Zeolite ◽  
Oxidation Processes ◽  
Aging Conditions ◽  
Adsorption Desorption ◽  
Reference Samples ◽  
Exchange Technique

The present work is aim to study the adsorption/desorption properties of the Ag-modified Y zeolite towards toluene as well as its high temperature behavior under the prompt thermal aging conditions. The Ag/Y samples were obtained by an ion exchange technique and mixed with pure alumina used as a binder. The reference samples were prepared by an incipient wetness impregnation of alumina with a solution of silver nitrate and mixed with pure HY zeolite. The initial and aged samples were characterized by TEM and XRD methods. It was found that the Ag-modified Y zeolite strongly adsorbs toluene. Irreversible sorption of toluene over the most active silver sites was shown to exclude them from the participation in oxidation processes, thus diminishing the overall efficiency of the adsorption-catalytic system.

scholarly journals Cellulose nanocrystals (CNCs) as hard templates for preparing mesoporous zeolite Y assemblies with high catalytic activity

2020 ◽  
Vol 22 (15) ◽  
pp. 5115-5122 ◽  
Author(s):  
Samer Abdulridha ◽  
Jiuxing Jiang ◽  
Shaojun Xu ◽  
Zhaoxia Zhou ◽  
He Liang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Cellulose Nanocrystals ◽  
Zeolite Y ◽  
Synthesis Method ◽  
High Catalytic Activity ◽  
Mesoporous Zeolite ◽  
Y Zeolite ◽  
Directed Synthesis

Faujasite (FAU) Y zeolite assemblies with high mesoporosity (Sext = 347 m2 g−1 and Vmeso = 0.52 cm3 g−1) were synthesised using sustainable and economic cellulose nanocrystals (CNCs) via a template-directed synthesis method.

scholarly journals Temperature-Dependent Raman Spectroscopic Study of the Double Molybdate KBi(MoO4)2

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5453
Author(s):  
Min Wang ◽  
Changhao Wang ◽  
Jian Wang ◽  
Liming Lu ◽  
Xiaoye Gong ◽  
...  
Keyword(s):  
High Temperature ◽  
Raman Spectra ◽  
Monoclinic Phase ◽  
Raman Band ◽  
Vibrational Modes ◽  
Temperature Dependent ◽  
Raman Spectroscopic ◽  
Thermal Stability Of ◽  
Good Agreement

In situ high-temperature Raman spectra of polycrystalline KBi(MoO4)2 were recorded from room temperature to 1073 K. Thermal stability of the monoclinic KBi(MoO4)2 was examined by temperature-dependent XRD. The monoclinic phase transformed into the scheelite tetragonal structure at 833 K, and then to the monoclinic phase at 773 K. Quantum chemistry ab initio calculation was performed to simulate the Raman spectra of the structure of KBi(MoO4)2 high-temperature melt. The experimental Raman band at 1023 K was deconvoluted into seven Gaussian peaks, and the calculated results were in good agreement with the experimental data. Therefore, the vibrational modes of Raman peaks of molten KBi(MoO4)2 were assigned. It was confirmed that the isolated structure of [Bi(MoO4)2]− monomer, consisting of Mo6+ centers and Bi3+ sub-centers connected by edge-sharing, mainly exists in the melt of KBi(MoO4)2.

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