Comparison of HZSM-5 Zeolite and SAPO-5 Molecular Sieve in 1-Hexanol Conversion

1992 ◽  
Vol 57 (4) ◽  
pp. 739-744 ◽  
Author(s):  
Yuri A. Kalvachev ◽  
Cvetana P. Bezouhanova ◽  
Hans Lechert
Keyword(s):  
Ir Spectra ◽  
Carbonyl Compound ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Room Temperature ◽  
Olefin Isomerization ◽  
Positional Isomerization

The IR spectra of 1-hexanol adsorbed on SAPO-5 molecular sieves and on HZSM-5 zeolite were compared. It has been found, that both types of catalysts activate at 423 K the dehydration of 1-hexanol. In the IR spectra bands at 670 cm-1 (Z-isomer), 889 cm-1 (CH2=C< fragment), 911 cm-1 (CH2=CH-) and 965 cm-1 (E-isomer) have been observed, indicating that the skeletal and positional isomerization took place. A carbonyl compound (1730 cm-1) was formed at room temperature on all the investigated catalysts and disappeared upon heating. The activity of HZSM-5 in olefin isomerization and in dehydrogenation was greater than that of SAPO-5.

scholarly journals An Investigation on the Sound Absorption Performance of Granular Molecular Sieves under Room Temperature and Pressure

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1936
Author(s):  
Bing Zhou ◽  
Jiangong Zhang ◽  
Xin Li ◽  
Bilong Liu
Keyword(s):  
Layer Thickness ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Sound Absorption ◽  
Room Temperature ◽  
Acoustical Parameters ◽  
Pellet Size ◽  
Impedance Tubes ◽  
Absorption Performance ◽  
Temperature And Pressure

The sound absorption of granular silica-aluminate molecular sieve pellets was investigated in this paper. The absorption coefficients of molecular sieve pellets with different pore sizes, pellet sizes, and layer thicknesses were measured through impedance tubes under room temperature and pressure conditions. The effects of pore size, pellet size, layer thickness were compared and explained. The comparisons show that at room temperature and pressure, the sound absorption of molecular sieve pellets is not a result of the crystalline structure, but rather it mainly changes with the pellet size and layer thickness. In addition, the five non-acoustical parameters of molecular sieve pellets were obtained by an inverse characterization method based on impedance tube measurements. The measurement by impedance tubes is in good agreement with the calculation of Johnson-Champoux-Allard (JCA) model, proving that the JCA model can be effectively used to predict the sound absorption of molecular sieve pellets.

Improvement of Adsorption Performance Based on Metal Ion Modified ETS-4 Molecular Sieves

2013 ◽  
Vol 815 ◽  
pp. 437-442 ◽  
Author(s):  
Li Yun Song ◽  
Xiao Jun Liu ◽  
Zong Cheng Zhan ◽  
Hong He ◽  
Xue Hong Zi ◽  
...  
Keyword(s):  
Molecular Sieves ◽  
Molecular Sieve ◽  
Metal Ion ◽  
Room Temperature ◽  
Raw Materials ◽  
Ni Doping ◽  
Adsorption Performance ◽  
Adsorption Capacities ◽  
Titanium Trichloride ◽  
Significant Change

Titanosilicate ETS-4 with the Sr and Ni cations modification were prepared by hydrotherrmal method using titanium trichloride and tetraethoxysilane as raw materials. The properties and morphology of the materials were characterized by XRD, SEM techniques, Sr and Ni introduced to the molecular sieve affected the frame contraction when they were heated, and did little effect on the crystallization and morphology. N2and CH4isotherms of each sample were measured at room temperature. The Sr and Ni doping could improve the N2and CH4adsorption capacities of ETS-4. The capacities of the two gases increased in the pressurization process for ETS-4-Sr and ETS-4-Ni, with the pressure increasing, no significant change in capacities of N2and CH4was observed over the ETS-4 sample. Compared to ETS-4 molecular sieves, the capacity for N2of ETS-4-Sr and ETS-4-Ni at the pressure of 1200 mmHg increased 4.2 and 3.9 times, respectively. At last, the results indicated that the cations doping (Sr2+and Ni2+) can improve the adsorption performance of ETS-4 greatly.

Catalytic decomposition and mechanism of formaldehyde over Pt–Al2O3 molecular sieves at room temperature

2017 ◽  
Vol 19 (10) ◽  
pp. 6957-6963 ◽  
Author(s):  
Xiaofeng Zhu ◽  
Jiaguo Yu ◽  
Chuanjia Jiang ◽  
Bei Cheng
Keyword(s):  
Molecular Sieves ◽  
Molecular Sieve ◽  
Room Temperature ◽  
Catalytic Decomposition ◽  
Formaldehyde Oxidation

Al2O3 molecular sieve supported Pt was prepared for catalytic formaldehyde oxidation at room temperature.

Fibrillin molecules aggregate to form an extendible beaded structure which is a major component of “Elastin Associated” microfibrils

1989 ◽  
Vol 47 ◽  
pp. 246-247
Author(s):  
Douglas R. Keene ◽  
B. Kerry Maddox ◽  
Marie B. Spurgin ◽  
Lynn Y. Sakai ◽  
Robert W. Glanville
Keyword(s):  
Molecular Sieve ◽  
Room Temperature ◽  
Culture Medium ◽  
Weight Fraction ◽  
Ammonium Bicarbonate ◽  
High Molecular Weight Fraction ◽  
Bicarbonate Buffer ◽  
Human Amnion ◽  
Gold Conjugate ◽  
Ammonium Bicarbonate Buffer

A mouse monoclonal antibody was used to identify beaded aggregates found in guanidine extracts of human amnion as assemblies of fibrillin molecules. These aggregates were also shown to be a major component of extracellular matrix microfibrils. We further demonstrated that the periodicity of these aggregates can be increased when subjected to mechanical stress.Human amnion was extracted with guanidine and the extracted material purified using ion exchange and molecular sieve chromatography. A high molecular weight fraction was precipitated by dialyzing against dilute acetic acid. Part of the precipitate was suspended in 0.2 M ammonium bicarbonate buffer and rotary shadowed. A second portion was resuspended in culture medium containing antibody which recognizes matrix microfibrils, diluted 1:5 in ammonium bicarbonate and reacted for 120 minutes at room temperature. Antibody labeled precipitate was washed by repeated pelleting and resuspension in buffer and then incubated in Janssen GAM 5 nm gold conjugate for 60 minutes at room temperature.

Circular dichroism and infrared study of β-turn formation in repeat peptides of elastin

1987 ◽  
Vol 52 (5) ◽  
pp. 1356-1361
Author(s):  
S. Abdel Rahman ◽  
M. Elsafty ◽  
A. Hattaba
Keyword(s):  
Circular Dichroism ◽  
Solid State ◽  
Ir Spectra ◽  
Chain Length ◽  
Room Temperature ◽  
Infrared Study ◽  
Feature Characteristic ◽  
C 50 ◽  
The Stability ◽  
Circular Dichroïsm

The conformation of elastin-like peptides Boc-Ala-Pro-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Ala-Pro-Gly-Val-Gly-Val-APEGM, Boc-Ala-Pro-Gly-Val-Gly-Val-Ala-Pro-Gly-Val-Gly-Val-APEGM were examined in solution using circular dichroism at 30 °C, 50 °C, and 70 °C and in solid state by IR at room temperature. The studies show that the β-turn is a significant conformational feature for peptides under investigation in solution at 30 °C and 50 °C, but at 70 °C the tetra, hexa, and decapeptides show the CD feature characteristic of the β-structure while the dodecapeptide spectra show the presence of β-turn which indicates the stability of the β-turn at this chain length. The IR spectra show that in the solid state at room temperature all investigated peptides assume essentially a β-turn except the tetrapeptide which present evidence of antiparallel β-structure. The β-turn contribution in the IR spectra increases with the increase of the chain length of the peptide.

Preparation and Characterization of Ni-Containing Aluminophosphate Molecular Sieves

2011 ◽  
Vol 418-420 ◽  
pp. 617-620
Author(s):  
Ying Sun ◽  
Lan Ying Ge
Keyword(s):  
Oxidation State ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Crystalline Form ◽  
Spectroscopic Techniques ◽  
Tetrahedral Coordination ◽  
Tetrahedral Geometry ◽  
Nickel Ions ◽  
Aluminophosphate Molecular Sieves

Aluminophosphate molecular sieve and Ni(II)-containing APO-5 materials were synthesized hydrothermally and characterized by various analytical and spectroscopic techniques. It indicates that the nickel ions with a divalent oxidation state can incorporate into the tetrahedral coordination in mesoporous aluminophosphate very well. The better crystallizing temperature is explored. A stronger crystalline form is obtained with the addition of HF. Further, microporous aluminophosphate molecular sieves and Ni(II) ions remain in a tetrahedral geometry even after calcination at 550 °C.

Progress in Synthesis of Micro- and Mesoporous Composite Molecular Sieve

2011 ◽  
Vol 396-398 ◽  
pp. 1151-1156
Author(s):  
Wen Yuan Wu ◽  
Chun Wei Shi ◽  
Xue Bian
Keyword(s):  
Hydrothermal Synthesis ◽  
Microwave Radiation ◽  
Vapor Phase ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Vapor Phase Transport ◽  
Mesoporous Composite ◽  
Composite Molecular Sieve ◽  
Potential Applications ◽  
Phase Transport

Micro- and mesoporous composite molecular sieves enable to achieve grades distribution of pore sizes and appropriate collocation of acidity,which have potential applications in catalysis and adsorption of large molecules.This review focus on some of the most recent results during the last decades.The techniques applied to synthesize different micro-mesoporous composite molecular sieves includes single template, dual template, crystallization of mesoporous walls, alkaline desilication, vapor-phase transport synthesis,and microwave radiation hydrothermal synthesis.

Ultra-facile aqueous synthesis of nanoporous zeolitic imidazolate framework membranes for hydrogen purification and olefin/paraffin separation

2019 ◽  
Vol 7 (18) ◽  
pp. 10898-10904 ◽  
Author(s):  
Xu Jiang ◽  
Songwei Li ◽  
Yongping Bai ◽  
Lu Shao
Keyword(s):  
Aqueous Solution ◽  
Gas Separation ◽  
Molecular Sieve ◽  
Room Temperature ◽  
Hydrogen Purification ◽  
Step Method ◽  
Zeolitic Imidazolate Framework ◽  
Aqueous Synthesis ◽  
One Step

An ultra-facile one-step method is discovered to synthesize defect-free ZIF-8 molecular sieve membranes in aqueous solution at room temperature for exceptional gas separation.

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