Structure of Al–Lewis Site in Beta Zeolite Active in the Meerwein–Ponndorf–Verley Reduction of Ketone to Alcohol

2002 ◽  
Vol 210 (1) ◽  
pp. 171-182 ◽  
Author(s):  
O Bortnovsky
Keyword(s):  
Beta Zeolite ◽  
Lewis Site

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>

Ultrafast synthesis of high-silica Beta zeolite from dealuminated MOR by interzeolite transformation for methanol to propylene reactions

2021 ◽  
Vol 314 ◽  
pp. 110894
Author(s):  
Bowen Wang ◽  
Li Ren ◽  
Jingyan Zhang ◽  
Rusi Peng ◽  
Shaoqing Jin ◽  
...  
Keyword(s):  
Beta Zeolite ◽  
High Silica

Characterization and catalytic properties of a saponite clay modified by acid activation

Clay Minerals ◽  
1997 ◽  
Vol 32 (4) ◽  
pp. 633-643 ◽  
Author(s):  
F. Kooli ◽  
W. Jones
Keyword(s):  
Infrared Spectroscopy ◽  
Room Temperature ◽  
Textural Properties ◽  
Acid Sites ◽  
Single Type ◽  
Activation Process ◽  
Acid Activation ◽  
Strongly Correlated ◽  
Lewis Site ◽  
Adsorbed Pyridine

AbstractA natural saponite was acid activated at room temperature or 90°C with different acid/clay ratios and the products were characterized by powder X-ray diffraction, infrared spectroscopy and thermogravimetry. The leaching of Mg from the octahedral sheets is enhanced by an increase in the acid/clay ratio and by an increase in temperature of activation. Textural properties are reported, and it appears that they are strongly correlated to the presence of a noncrystalline silica phase which is formed during the acid activation process. The desorption of cyclohexylamine indicates that for samples activated at 90°C the number of acid sites in the acidactivated saponites decreases following severe acid treatment. Infrared spectroscopy of adsorbed pyridine on samples after calcination at 500°C suggests that acid activation at 90°C produces a single type of Bronsted site but two types of Lewis sites whereas activation at room temperature results in only one type of Lewis site in addition to a Brønsted site. The two Lewis sites are suggested to originate from residual Al in the clay structure and to AI exsolved from the layers during activation. The dehydration of pentan-1-ol has been used as a further probe to measure acidity by monitoring the degree of conversion and selectivity for the different samples.

Oligomerization of isobutene with a beta-zeolite membrane: Effect of the acid properties of the catalytic membrane

2011 ◽  
Vol 166 (1) ◽  
pp. 205-208 ◽  
Author(s):  
M. Torres ◽  
M. Gutiérrez ◽  
V. Mugica ◽  
M. Romero ◽  
L. López
Keyword(s):  
Zeolite Membrane ◽  
Beta Zeolite ◽  
Catalytic Membrane ◽  
Acid Properties ◽  
Membrane Effect

scholarly journals High-efficiency catalytic performance over mesoporous Ni/beta zeolite for the synthesis of quinoline from glycerol and aniline

RSC Advances ◽  
2017 ◽  
Vol 7 (16) ◽  
pp. 9551-9561 ◽  
Author(s):  
An Li ◽  
Chen Huang ◽  
Cai-Wu Luo ◽  
Wen-Jun Yi ◽  
Zi-Sheng Chao
Keyword(s):  
Catalytic Activity ◽  
Vapor Phase ◽  
High Efficiency ◽  
Zeolite Catalyst ◽  
Catalytic Performance ◽  
Beta Zeolite ◽  
Phase Process

Quinoline was synthesized via the typical Skraup approach with a vapor-phase process. The mesoporous Ni/beta zeolite catalyst exhibited high-efficiency catalytic activity and an enhanced ability of anti-deactivation.

Study of the reductive solid-state ion exchange of indium into an NH4-beta zeolite

1998 ◽  
Vol 24 (4-6) ◽  
pp. 143-151 ◽  
Author(s):  
R.M. Mihályi ◽  
H.K. Beyer ◽  
V. Mavrodinova ◽  
Ch. Minchev ◽  
Y. Neinska
Keyword(s):  
Solid State ◽  
Ion Exchange ◽  
Beta Zeolite

scholarly journals An Investigation into the Adsorption of Aniline from Aqueous Solution Using H-Beta Zeolites and Copper-Exchanged Beta Zeolites

2005 ◽  
Vol 23 (3) ◽  
pp. 255-266 ◽  
Author(s):  
J. O'Brien ◽  
T. Curtin ◽  
T.F. O'Dwyer
Keyword(s):  
Aqueous Solution ◽  
Adsorption Process ◽  
Zeolite Beta ◽  
Langmuir Model ◽  
Beta Zeolite ◽  
Copper Leaching ◽  
Beta Zeolites ◽  
The Stability ◽  
Ph Range ◽  
Adsorbent Materials

Zeolite beta, a large-pore zeolite, was investigated in this study with a view to examining it as a potential adsorbent for the removal of aniline from aqueous solutions. Two different metal-loaded zeolites were prepared by exchanging H-beta zeolite (SiO2/Al2O3 = 75:1) with copper. The influence of exchanged copper on the uptake level was assessed. The effect of varying the silica-to-alumina ratio of the H-beta zeolite on the aniline uptake level was also examined, using three different H-beta zeolites with ratios of 25:1, 75:1 and 150:1 as adsorbents. The sorption experiments indicated an uptake level of ca. 110–120 mg/g for each zeolite and this level was also adsorbed by the copper-modified H-beta zeolites (SiO2/Al2O3 = 75:1). In all cases, the adsorption process followed the Langmuir model for adsorption and the level of aniline adsorbed was largely unaffected by a change in temperature or the presence of extra framework copper. The stability of the exchanged copper on these zeolites was then examined by measuring the quantity of copper leached from each zeolite into solution as a function of pH. Minimum copper leaching was observed in the pH range 5–11. This provided a stable pH working range for the adsorbent materials.

Effect of silica source on the synthesis, property and catalytic performance of Sn-Beta zeolite

2021 ◽  
pp. 124995
Author(s):  
Shengqiang Zhou ◽  
Lipeng Zhou ◽  
Yunlai Su ◽  
Xiaomei Yang ◽  
Hao He
Keyword(s):  
Catalytic Performance ◽  
Beta Zeolite ◽  
Silica Source
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