A Novel Zeolite-Containing Composite Material Synthesized via In Situ Crystallization

2014 ◽  
Vol 926-930 ◽  
pp. 32-35
Author(s):  
Shu Qin Zheng ◽  
Shao Ren ◽  
Jian Ce Zhang ◽  
Wei Zhu

A novel Y zeolite-containing composite material was prepared via in situ crystallization with sepiolite and catalyst residue as starting materials, of which the BET surface area is up to 582 m2/g, the pore volume is 0.43 cm3/g, the relative crystallinity is as high as 55.7 %, the surface is smooth and regular, and Y zeolite particles are in the range of 0.4-1.0 mirons, the composite contains large number Y zeolite with more meso-macro porous structure.The alkalinity in reaction medium has a pronounced effect on the relative crystallinity of Y zeolite.

Author(s):  
Reza Yazdanpanah ◽  
Eshagh Moradiyan ◽  
Rouein Halladj ◽  
Sima Askari

Aim and Objective: The research focuses on recent progress in the production of light olefins. Hence, the common catalyst of the reaction (SAPO-34) deactivates quickly because of coke formation, we reorganized the mechanism combining SAPO-34 with a natural zeolite in order to delay the deactivation time. Materials and Methods: The synthesis of nanocomposite catalyst was conducted hydrothermally using experimental design. Firstly, Clinoptilolite was modified using nitric acid in order to achieve nano scaled material. Then, the initial gel of the SAPO-34 was prepared using DEA, aluminum isopropoxide, phosphoric acid and TEOS as the organic template, sources of Aluminum, Phosphor, and Silicate, respectively. Finally, the modified zeolite was combined with SAPO-34's gel. Results: 20 different catalysts due to D-Optimal design were synthesized and the nanocomposite with 50 weight percent of SAPO-34, 4 hours Crystallization and early Clinoptilolite precipitation showed the highest relative crystallinity, partly high BET surface area and hierarchical structure. Conclusion: Different analysis illustrated the existence of both components. The most important property alteration of nanocomposite was the increment of pore mean diameters and reduction in pore volumes in comparison with free SAPO-34. Due to low price of Clinoptilolite, the new catalyst develops the economy of the process. Using this composite, according to formation of multi-sized pores located hierarchically on the surface of the catalyst and increased surface area, significant amounts of Ethylene and Propylene, in comparison with free SAPO-34, were produced, as well as deactivation time that was improved.


2017 ◽  
Vol 11 (5) ◽  
pp. 47 ◽  
Author(s):  
Heman A. Smail ◽  
Kafia M. Shareef ◽  
Zainab H. Ramli

The adsorption of lead (Pb II) ion on different types of synthesized zeolite was investigated. The BET surface area, total pore volume & average pore size distribution of these synthesized zeolites were determined by adsorption isotherms for N2, the surface area & total pore volume of their sources were found by adsorption isothermN2.The adsorption equilibrium was measured after 24h at room temperature (RT) & concentration 10mg.L-1 of Pb (II) was used. The adsorption of heavy metal Pb (II) on four different prepared zeolites (LTA from Montmorillonite clay, FAU(Y)-B.H (G2) from Barley husk, Mordenite (G1) from Chert rock, FAU(X)-S.C (G3) from shale clay & modified Shale clay by oxalic acid (N1) & sodium hydroxide (N2)), were compared with the adsorption of their sources by using static batch experimental method. The major factors affecting the heavy metal ion sorption on different synthesized zeolites & their sources were investigated. The adsorption equilibrium capacity (Qm) of Pb (II) ion for different synthesized zeolites ordered from (N1>N2>LTA>G3>G2>G1&for their sources ordered Shale clay >Montmorilonite> Barley husk>Chert rock. The atomic absorption spectrometry was used for analysis of lead heavy metal ion, the obtained results in this study showed that the different synthesized zeolites were efficient ion exchanges for removing heavy metal, in particular, the modified zeolite from shale clay by oxalic acid.


2020 ◽  
Vol 56 (49) ◽  
pp. 6715-6718 ◽  
Author(s):  
Zi-Jian Li ◽  
Yu Ju ◽  
Bowen Yu ◽  
Xiaoling Wu ◽  
Huangjie Lu ◽  
...  

Isoreticular expansion of Th-MOFs via modulated synthesis yielded seven hierarchical complexes with superior quality single crystals, record high void space and BET surface area among Th materials, and exceptional iodine adsorption capacities.


1997 ◽  
Vol 15 (6) ◽  
pp. 465-476 ◽  
Author(s):  
G.A. El-Shobaky ◽  
A.M. Ghozza ◽  
G.M. Mohamed

Two samples of Cr2O3/Al2O3 were prepared by mixing a known mass of finely powdered Al(OH)3 with a calculated amount of CrO3 solid followed by drying at 120°C and calcination at 400°C. The amounts of chromium oxide employed were 5.66 and 20 mol% Cr2O3, respectively. The calcined solid specimens were then treated with different doses of γ-rays (20–160 Mrad). The surface and catalytic properties of the different irradiated solids were investigated using nitrogen adsorption at −196°C and the catalysis of CO oxidation by O2 at 300–400°C. The results revealed that γ-rays brought about a slight decrease in the BET surface area, SBET (15%), and in the total pore volume, Vp (20%), of the adsorbent containing 5.66 mol% Cr2O3. The same treatment increased the total pore volume, Vp (36%), and the mean pore radius, r̄ (43%), of the other adsorbent sample without changing its BET surface area. The catalytic activities of both catalyst samples were found to increase as a function of dose, reaching a maximum value at 80–160 Mrad and 40 Mrad for the solids containing 5.66 and 20 mol% Cr2O3, respectively. The maximum increase in the catalytic activity measured at 300°C was 59% and 100% for the first and second catalyst samples, respectively. The induced effect of γ-irradiation on the catalytic activity was an increase in the concentration of catalytically active sites taking part in chemisorption and in the catalysis of CO oxidation by O2 without changing their energetic nature. This was achieved by a progressive removal of surface hydroxy groups during the irradiation process.


2019 ◽  
Vol 944 ◽  
pp. 1192-1198
Author(s):  
Rong Wang ◽  
Zhi Xiang Lin ◽  
Yang Zhao ◽  
Xiao Dong Xu ◽  
Yan Xi Deng

An Al-supported cage-like mesoporous silica type MCM-41 has been prepared using a simple one-step synthetic procedure using oil shale residue and CTAB(Hexadecyl trimethyl Ammonium Bromide) as the template. The effects of temperature on the porosity, structure and surface area of Al-MCM-41 mesoporous materials were characterized by X-ray powder diffraction, N2adsorption desorption, scanning electron micrographs (SEM), transmission electron microscopy (TEM) techniques and Fourier transform infrared spectroscopy (FT-IR). The results indicated that temperature was a key to the characteristics of Al-MCM-41 materials, and when the temperature up to 333 K, Al-MCM-41 exhibited excellent characteristics with high degree of order, high surface area and pore volume. The one-step hydrothermal synthesized MCM-41 mesoporous material possessed high BET surface area, high pore size and high pore volume. They are respectively 835.1 m2/g, 32.6 Å and 1.22 cm3/g under the condition of the Si : Al =78:1, pH =10, crystallization temperature was 333K, crystallization time was 48h and calcination at 823 K for 5 h in air. All the results indicated the possibility of using oil shale residue as silicon and aluminum source to produce Al-MCM-41, and gave us a new way to recycle a solid waste. As well as this made it impossible to large-scale production of Al-MCM-41. Keywords: Al-MCM-41 mesoporous materials, oil shale residue, one-step synthesis


Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1764
Author(s):  
Sarah Zayan ◽  
Ahmed Elshazly ◽  
Marwa Elkady

Composite metal–organic frameworks combine large and accessible surface areas with low density and high stability. Herein, we present novel nanocomposites of polypyrrole/aluminum fumarate metal–organic framework (PPy/AlFu MOF), which were synthesized via in situ oxidative polymerization with the aim of MOF functionalization to enhance its thermal stability and increase the specific surface area so that these nanocomposites may be used as potential adsorbents. The synthesized nanocomposites were characterized by various techniques, such as powder X-ray diffraction, scanning electron microscopy, and Fourier-transform infrared spectroscopy (FTIR). The successful functionalization of aluminum fumarate MOF was confirmed by FTIR, and the Brunauer–Emmett–Teller (BET) surface area of the PPy/MOF nanocomposite slightly increased from 795 to 809 m2/g. Thermogravimetric analysis data also show that the weight loss of the composite is up to 30% at temperatures up to 500 ℃. Remarkably, lead (50 ppm) sequestration using the composite was tested, and the atomic absorption spectrometry data demonstrate that PPy/MOF is a super-adsorbent for heavy metal ions. This work shows that the novel polymer–MOF composites are promising materials for the selective removal of lead from wastewater streams.


2010 ◽  
Vol 148-149 ◽  
pp. 1096-1099
Author(s):  
Gong Ming Peng ◽  
De Lian Yi ◽  
Lin Wu ◽  
Zhao Hui Ou Yang ◽  
Jian Guo Wang

Novel base catalysts were obtained by subjecting Y zeolites to nitridation. These materials were characterized by elemental analysis, X-ray diffraction, BET surface area analysis, In situ diffuse reflectance infrared fourier transform Spectroscopy (in situ DRIFTS), Pyrrole adsorption. The results indicated nitrogen-incorporated NaY zeolite was well ordered and possess high surface area and pore volume. In situ DRIFTS experiments confirmed that N atoms had been introduced into the framework by nitridation to form -NH2- or -NH- species. It was found that Lewis basicity of these oxynitride materials increased by the pyrrole adsorption. Furthmore, the basic catalytic properties of nitrogen-incorporated zeolites were evaluated by Knoevenagal condensation of benzaldehyde with diethyl malonate and enhanced yield of product was achieved.


2019 ◽  
Vol 2 (3) ◽  
pp. 1205-1209
Author(s):  
Hasan Sayğılı

The influence of carbonization temperature (CT) on pore properties of the prepared activated carbon using lentil processing waste product (LWP) impregnated with potassium carbonate was studied. Activated carbons (ACs) were obtained by impregnation with 3:1 ratio (w/w) K2CO3/LWP under different carbonization temperatures at 600, 700, 800 and 900 oC for 1h. Activation at low temperature represented that micropores were developed first and then mesoporosity developed, enhanced up to 800 oC and then started to decrease due to possible shrinking of pores. The optimum temperature for LWP was found to be around 800 oC on the basis of total pore volume and the Brunauer-Emmett-Teller (BET) surface area. The optimum LWPAC sample was found with a CT of 800 oC, which gives the highest BET surface area and pore volume of 1875 m2/g and 0.995 cm3/g, respectively.


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Wen Liu ◽  
Tong-Tong Wang ◽  
Xiao-Luan Tang ◽  
Fei-Ya Jiang ◽  
Xiao Yan ◽  
...  

In this work, quercetin was loaded in the highly-porous lactose via the adsorption of quercetin molecules in ethanol. The method aims to improve the quercetin solubility and the loading capacity of lactose. The method relates to the synthesis of the highly-porous lactose with a particle size of ∼35 μm, a mean pore width of ∼30 nm, a BET surface area of 35.0561 ± 0.4613 m2/g, and a BJH pore volume of ∼0.075346 cc/g. After the quercetin loading in ethanol, BET surface area and BJH pore volume of porous lactose were reduced to 28.8735 ± 0.3526 m2/g and 0.073315 cc/g, respectively. The reduction rate was based on the quercetin loading efficiency of highly-porous lactose. DSC analysis and XRD analysis suggest that the sediments of quercetin in the nanopores of porous lactose are crystalline. FTIR spectroscopy results suggest that there is no significant interaction between quercetin and lactose. The highly-porous lactose had a higher loading efficiency of 20.3% (w/w) compared to the α-lactose (with 5.2% w/w). The release rates of quercetin from the highly-porous lactose tablets were faster compared to the conventional α-lactose carrier.


2018 ◽  
Vol 34 (5) ◽  
pp. 2661-2666
Author(s):  
Sadiq A. Karim

Condensation polymerisation technique has been employed to synthesise a Novel Tröger base polymer with thermal stability and microporosity. The synthesis process starts with alkylating anthracene, then nitrating and reducing this to produce the monomer. A Tröger base polymer is obtained by polymerising the monomer to afford a white polymer with good solubility into dichloromethane and chloroform, good thermal stability to ~377oC and a good BET surface area of 368.6 m2/g with a total pore volume of 0.4166 ml/g.


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