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.

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.

Different Modification Methods of Molecular Sieves Influence on CO2 Adsorption Performance

2012 ◽  
Vol 248 ◽  
pp. 250-255
Author(s):  
Chang Zi Wu ◽  
Bao Sheng Jin ◽  
Lu Lu Yu ◽  
Min Song ◽  
Zhao Ping Zhong
Keyword(s):  
Molecular Sieves ◽  
X Ray Diffraction ◽  
Amino Groups ◽  
Preparation Methods ◽  
X Ray ◽  
Adsorption Performance ◽  
Adsorption Capacities ◽  
Different Types ◽  
Mcm 41 ◽  
Co2 Adsorbent

In this work, different types of amine-attached MCM-41 are prepared with different preparation methods. The poly (ethyleneimine) (PEI) and γ-(aminopropyl) triethoxysilane (APTS) are attached to the pore surface of MCM-41 silica. The comparison between impregnation of PEI and covalence attachment of APTS to the MCM-41 support are investigated. X-ray diffraction, Roman spectra, and Thermal analysis are used to characterize the obtained samples. The characterization results confirm that the amino groups are attached to the pore structure of MCM-41. The CO2 adsorption capacities of different amine attached MCM-41 silicas are investigated employing CO2 adsorption isotherm. MCM-41-APTS show a considerable CO2 uptake, suggesting their potential usage for the CO2 adsorbent.

scholarly journals Optimized Preparation of Nanosized Hollow SSZ-13 Molecular Sieves with Ultrasonic Assistance

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2298
Author(s):  
Liang Zhou ◽  
Runlin Han ◽  
Yuxuan Tao ◽  
Jinqu Wang ◽  
Yiwei Luo
Keyword(s):  
Adsorption Capacity ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Co2 Adsorption ◽  
Hollow Structure ◽  
Preparation Time ◽  
Cubic Crystal ◽  
Adsorption Performance ◽  
Ultrasonic Time ◽  
Co2 Adsorption Capacity

Because of its unique eight-membered ring pore structure and the arrangement of cations in its structure, the SSZ-13 molecular sieve has a higher affinity for CO2 than other gases, meaning it has attracted more attention than other porous materials for CO2 adsorption. However, the expensive template and long preparation time limits the industrial production of SSZ-13. In this work, a hollow structure was successfully introduced into the nanosized SSZ-13 molecular sieve with ultrasonic treatment. The effects of the amount of seed added and the ultrasonic time on the structure were investigated. When the amount of seed added was 0.5 wt.% and the ultrasonic time was 60 min, the sample showed a hollow cubic crystal with a diameter of about 50 nm. The specific surface area reached 791.50 m2/g, and the mesoporous ratio was 66.3%. The samples were tested for CO2 adsorption performance at 298 K. It was found that the hollow sample prepared in this work has higher CO2 adsorption capacity compared with the SSZ-13 zeolite prepared with conventional methods. When the adsorption pressure was 0.27 bar, the adsorption amount reached 2.53 mmol/g. The hollow SSZ-13 molecular sieve reached a CO2 adsorption capacity of 4.24 mmol/g at 1 bar.

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 Growth Study of Hierarchical Pore SSZ-13 Molecular Sieves with Improved CO2 Adsorption Performance

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3171
Author(s):  
Runlin Han ◽  
Yuxuan Tao ◽  
Liang Zhou
Keyword(s):  
Pore Structure ◽  
Molecular Sieves ◽  
Molecular Sieve ◽  
Co2 Adsorption ◽  
Fluoride Ions ◽  
Structure Directing Agent ◽  
Small Unit ◽  
Excellent Thermal Stability ◽  
Adsorption Performance ◽  
Hierarchical Pore

SSZ-13, with a unique pore structure and excellent thermal stability, showed a potential application in the adsorption and catalysis industry. In this work, Al(NO3)3 was used as an Al source to study the performance and morphology of the zeolite. The zeolite was prepared with an unconventional process by adding an Al source before the structure-directing agent and base. When inorganic oxygen-containing anions were introduced into the unconventional synthesis system, the crystals of the zeolite conform to the unconventional growth mode. The zeolites with large crystals were assembled from small unit nanocrystals. Extending the reaction time, aging time and adding fluoride ions introduced a multistage pore structure on the surface of the molecular sieve, which improved the CO2 adsorption performance. When aging for 24 h, reaction for 96 h, and the amount of fluorine added was 0.05 (F/Si), the sample had the best hierarchical pore structure. The SSZ-13 molecular sieve with an added amount of 0.1 (F/Si) has the highest CO2 adsorption performance. The adsorption amount was 4.55 mmol/g at 1 bar, which is 20.4% higher than that of zeolite SSZ-13 prepared by the conventional process.

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.

Preparation of High-Purity Ultrafine α-Al2O3 by Solid-State Reaction at Room Temperature

2008 ◽  
Vol 368-372 ◽  
pp. 683-685
Author(s):  
Cheng Wei Hao ◽  
Bo Lin Wu ◽  
Ji Yan Li
Keyword(s):  
Solid State ◽  
High Purity ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Raw Materials ◽  
Phase Particle ◽  
Phase Transformation Temperature ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
Α Al2o3

Ammonium aluminium carbonate hydroxide (AACH), with a small quantity of γ-AlOOH, was synthesized through solid-state reaction at room temperature using AlCl3·6H2O and NH4HCO3 as raw materials and polyethylene glycol (PEG-10000) as the dispersant. After calcined at 1100°C for 1.5h, α-Al2O3 powders with primary particle sizes of 20~30nm were obtained. The crystal phase, particle size and morphology of the high-purity ultrafine α-Al2O3 were characterized. The results showed that a small quantity of γ-AlOOH in the AACH decomposed and formed crystal seeds. The presence of crystal seeds reduced the nucleation activation energy and therefore reduced the phase transformation temperature.

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.

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