scholarly journals Al-Si@Al(OH)3 Nanosheets Composite for Enhanced Efficient Strategy to Synthesize Al-Si@Al2O3 Core-shell Structure

2021 ◽  
Author(s):  
Yuhui Lin ◽  
Panyu Chen ◽  
Ying Wang ◽  
Wei He ◽  
Chao Tang ◽  
...  
Keyword(s):  
Heat Storage ◽  
X Ray Diffraction ◽  
Storage Material ◽  
X Ray ◽  
Catalyst Carrier ◽  
Heat Storage Material ◽  
Desorption Isotherms ◽  
Si Content ◽  
Adsorption Desorption

Abstract Owing to the combined advantages of Al-Si alloy and Al2O3, Al-Si@Al2O3 is widely utilized as a heat storage material, catalyst carrier and what adsorption host. Hence, the preparation of Al-Si@Al2O3 and corresponding precursors is of utmost significance. Herein, Al-Si@Al(OH)3 precursor is investigated and Al(OH)3 nanosheets are in-situ formed on the surface of Al-xSi alloy (x = 10, 20 and 30) in the presence of water. The influence of Si content, diameter of Al-Si particles and heating parameters on morphology and thickness of Al(OH)3 nanosheets is systematically explored using X-ray diffraction, electron microscopy, Fourier transform infrared spectroscopy and N2 adsorption/desorption isotherms. The growth mechanism of Al(OH)3 nanosheets is revealed and a pathway to obtain Al-Si@Al2O3 nanosheets with desired structure and thickness is demonstrated.

Structure and Performance of Calcined Bauxite

2014 ◽  
Vol 887-888 ◽  
pp. 305-308 ◽  
Author(s):  
Bin Zheng Fang ◽  
Hui Li ◽  
Jian Wei Cao ◽  
Jian Feng Wu ◽  
Xiao Hong Xu ◽  
...  
Keyword(s):  
High Temperature ◽  
Heat Storage ◽  
X Ray Diffraction ◽  
Storage Material ◽  
X Ray ◽  
Temperature Performance ◽  
Heat Storage Material ◽  
Testing Technology ◽  
Crystal Phases ◽  
And Performance

In order to further broaden the application field of calcined bauxite, using differential thermal analysis-thermo-gravimetry (DTA-TG), X-ray diffraction analysis (XRD), Scanning electron microscopy (SEM) and other testing technology to study and analysis on the high temperature performance of calcined bauxite in this paper. The results show that the main crystal phases of calcined bauxite are corundum and mullite, appearance is layered, granular distribution. Due to the thermal performance of calcined bauxite is optimal, and is expected to be used for the field of high temperature solar thermal heat storage material.

scholarly journals Effect of Both the Phase Composition and Modification Methods on Structural-Adsorption Parameters of Dispersed Silicas

2018 ◽  
Vol 3 (1) ◽  
pp. 1 ◽  
Author(s):  
Tatyana Rakitskaya ◽  
Tatyana Kiose ◽  
Kristina Golubchik ◽  
Viacheslav Baumer ◽  
Vitaliya Volkova
Keyword(s):  
Water Vapor ◽  
Water Vapor Adsorption ◽  
X Ray Diffraction ◽  
Adsorption Parameters ◽  
X Ray ◽  
Vapor Adsorption ◽  
Crystallite Sizes ◽  
Desorption Isotherms ◽  
Adsorption Desorption ◽  
Modified Forms

Tripoli from two Ukrainian deposits was studied in its natural and modified forms. The investigation of natural and modified tripoli involves the identification of their phase compositions through X-ray diffraction and the analysis of their water vapor adsorption-desorption isotherms. The obtained results are evidence of changes in the structural-adsorption parameters of tripoli as a result of modification. Their treatment in boiling water or acid causes apparent alterations of contents of the main phases and sizes of their crystallites, whereas their calcination causes not only the dehydroxylation of surfaces and the agglomeration of phases, but even phase transformation in the case of carbonate tripoli. After analyzing water vapor adsorption-desorption isotherms of natural and modified tripolis, some correlations between their adsorption parameters, phase compositions, main phase contents and crystallite sizes have been found.

The Application of Mesoporous ZSM-5 Zeolite in the ULSD Catalysts

2020 ◽  
Vol 4 (4) ◽  
pp. 1-3
Author(s):  
Liu L
Keyword(s):  
Catalytic Performance ◽  
Nitrogen Compounds ◽  
In Situ Ftir ◽  
X Ray Diffraction ◽  
N2 Adsorption ◽  
X Ray ◽  
Acidic Sites ◽  
Adsorption Desorption ◽  
Al2o3 Catalyst

The mesoporous ZSM-5 zeolite containing MoCoP/Al2O3 catalyst (C12-ZSM5) with the mixture of Al2O3 and mesoporous ZSM- 5 zeolite as carrier was synthesized. The catalytic performance of C12-ZSM5 catalyst was evaluated by the hydrodesulfurization (HDS) of different diesel feedstock. The carriers and catalysts were characterized by N2 adsorption-desorption, pyridine-FTIR, X-ray diffraction (XRD) and CO in-situ FTIR (CO-FTIR) techniques. Results showed that mesoporous ZSM-5 can improve the acidity of the catalyst and increase the number of MoCoS active phases. The C12-ZSM5 catalyst had low HDS and HDN activity, because the acidic sites of mesoporous ZSM-5 were easily occupied by nitrogen compounds. The HDS activity of C12-ZSM5 catalyst was fully exploited by using graded packing technology, the sulfur content of product oil was 5.9 ng/μL. The relative HDS activity of C12-ZSM5 catalyst is 1.47 times that of FHUDS-8 catalyst.

Biosorption of crystal violet dye using inactive biomass of the fungus Diaporthe schini

2019 ◽  
Vol 79 (4) ◽  
pp. 709-717 ◽  
Author(s):  
Patrícia Grassi ◽  
Caroline Reis ◽  
Fernanda C. Drumm ◽  
Jordana Georgin ◽  
Denise Tonato ◽  
...  
Keyword(s):  
Crystal Violet ◽  
X Ray Diffraction ◽  
N2 Adsorption ◽  
Biosorption Capacity ◽  
X Ray ◽  
Crystal Violet Dye ◽  
Endothermic Process ◽  
Desorption Isotherms ◽  
Adsorption Desorption ◽  
Scanning Electron

Abstract An inactive biomass of a new fungus recently discovered, Diaporthe schini, was evaluated for the biosorption of crystal violet (CV) in simulated textile effluents. The characterization assays were performed using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and N2 adsorption/desorption isotherms. The influences of pH and biosorbent dosage on the biosorption capacity were evaluated. Kinetics, equilibrium and thermodynamic studies were also carried out. Characterization techniques showed an amorphous biosorbent, with a rough surface containing irregular particles and surface area of 6.5 m2 g−1. The most adequate values of pH and biosorbent dosage were 7.5 and 0.4 g L−1, respectively. The Elovich kinetic model and the Sips equilibrium model were suitable to fit the experimental data. The biosorption capacity increased with temperature, reaching a maximum biosorption capacity of 642.3 mg g−1 at 328 K. The biosorption was a spontaneous and endothermic process. Diaporthe schini inactive biomass was an interesting biosorbent to treat colored effluents, presenting efficiency of 87% in the decolorization of a simulated dye house effluent.

scholarly journals Efficiency of TiO2 catalyst supported by modified waste fly ash during photodegradation of RR45 dye

2019 ◽  
Vol 26 (1) ◽  
pp. 292-300 ◽  
Author(s):  
Vanja Gilja ◽  
Zvonimir Katančić ◽  
Ljerka Kratofil Krehula ◽  
Vilko Mandić ◽  
Zlata Hrnjak-Murgić
Keyword(s):  
Fly Ash ◽  
Gas Adsorption ◽  
Sol Gel ◽  
Efficiency Evaluation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sol Gel Synthesis ◽  
Adsorption Desorption

AbstractThe waste fly ash (FA) material was subjected to chemical treatment with HCl at elevated temperature for a different time to modify its porosity. Modified FA particles with highest surface area and pore volume were further used as a support for TiO2 catalyst during FA/TiO2 nanocomposite preparation. The nanocomposite photocatalysts were obtained by in situ sol–gel synthesis of titanium dioxide in the presence of FA particles. To perform accurate characterization of modified FA and FA/TiO2 nanocomposite photocatalysts, gas adsorption-desorption analysis, X-ray diffraction, scanning electron microscopy, UV/Vis and Infrared spectroscopy were used. Efficiency evaluation of the synthesized FA/TiO2 nanocomposites was performed by following the removal of Reactive Red 45 (RR45) azo dye during photocatalytic treatment under the UV-A irradiation. Photocatalysis has been carried out up to five cycles with the same catalysts to investigate their stability and the possible reuse. The FA/TiO2 photocatalyst showed very good photocatalytic activity and stability even after the fifth cycles. The obtained results show that successfully modified waste fly ash can be used as very good TiO2 support.

Synthesis and Characterization of the Catalysts 5 wt.% and 10 wt.% Co/SBA-15

2010 ◽  
Vol 660-661 ◽  
pp. 561-566
Author(s):  
L.A. Lima ◽  
B.V. Sousa ◽  
Meiry Glaúcia Freire Rodrigues
Keyword(s):  
Ethylene Oxide ◽  
Molecular Sieve ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
X Ray ◽  
Poly Ethylene Oxide ◽  
Desorption Isotherms ◽  
Poly Ethylene ◽  
Adsorption Desorption

Catalysts supported on SBA-15 were obtained by wet impregnation using aqueous solution of cobalt nitrate, where different contents of cobalt (5 wt% and 10 wt%) were prepared. The molecular sieve SBA-15 was synthesized using tetra ethyl ortho silicate (TEOS) as silicate source, and triblock copolymer, poly-(ethylene oxide)-poly (propylene oxide)-poly-(ethylene oxide) PEO-PPO-PEO as the organic structure directing agent. These materials were characterized by X-ray diffraction (XRD), X-ray energy dispersion spectrophotometer (EDX) and Nitrogen adsorption–desorption isotherms (BET). The results from the XRD showed that the molecular sieve mesoporous (SBA-15) was identified by X-ray diffraction, especially from the (210) and (300) peaks, which represent a typical spectrum for the SBA-15. Characterization of catalysts by Nitrogen adsorption–desorption isotherms (BET) made it possible to verify the the samples had been of type IV with hysteresis of corresponding the H2 type the porous materials.

scholarly journals The flexibility of modified-linker MIL-53 materials

2016 ◽  
Vol 45 (10) ◽  
pp. 4162-4168 ◽  
Author(s):  
Alexis S. Munn ◽  
Renjith S. Pillai ◽  
Shyam Biswas ◽  
Norbert Stock ◽  
Guillaume Maurin ◽  
...  
Keyword(s):  
Thermal Dehydration ◽  
X Ray Diffraction ◽  
X Ray ◽  
Methanol Adsorption ◽  
Adsorption Desorption

The flexibility of eight aluminium hydroxo terephthalates [Al(OH)(BDC–X)] (X = –H, –CH3, –Cl, –Br, –NH2, –NO2, –(OH)2, –CO2H) has been investigated upon thermal dehydration, superhydration and methanol adsorption/desorption using in situ powder X-ray diffraction.

scholarly journals Synthesis of Dimethyl Carbonate from CO2 and Methanol over Zr-Based Catalysts with Different Chemical Environments

Catalysts ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 710
Author(s):  
Linmeng Huo ◽  
Tian Wang ◽  
Keng Xuan ◽  
Lei Li ◽  
Yanfeng Pu ◽  
...  
Keyword(s):  
Dimethyl Carbonate ◽  
Lewis Acid Site ◽  
Catalytic Performance ◽  
Lewis Base ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
X Ray ◽  
Good Catalytic Activity ◽  
Adsorption Desorption

The adsorption and activation of both CO2 and methanol are mainly affected by the distance of the Lewis acid site, Zr4+, and Lewis base, Zr4+/O2−, of the Zr-based catalysts. In this paper, Zr-incorporated SBA-15 (Zr-SBA-15) and Zr-grafted SBA-15 (Zr/SBA-15) catalysts were prepared with different Zr environments, and were analyzed with N2 adsorption–desorption isotherms, X-ray diffraction, UV-vis spectra, and XPS. It was proposed that Zr-SBA-15 catalyst with Si-O-Zr-OH and Zr-O-Si-OH structure exhibited non-adjacent sites between Zr4+ and Zr4+/O2−, while Zr/SBA-15 catalyst with Zr-O-Zr-OH structure showed neighboring sites between Zr4+ and Zr4+/O2−. Furthermore, the Zr/SBA-15 catalyst exhibited good catalytic activity, while no DMC was detected over the Zr-SBA-15 catalyst at the same reaction conditions. For combined in situ infrared and catalytic performance, it was indicated that the methanol and CO2 could be activated to form DMC, only when the Zr4+ and Zr4+/O2− sites existed and were adjacent to each other in the Zr-O-Zr-OH of Zr/SBA-15 catalyst.

scholarly journals TiO2 Nanowire Arrays in situ Grown on Ti Foil Exhibiting Superior Uranyl-Adsorption Properties

2021 ◽  
Vol 8 ◽  
Author(s):  
Chun Chen ◽  
Yi Zhong ◽  
Xuxu Liu ◽  
Xijian Li ◽  
Jian Chu ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Nanowire Arrays ◽  
Aqueous Samples ◽  
X Ray Diffraction ◽  
Solution Ph ◽  
X Ray ◽  
Tio2 Nanowire ◽  
Ph Range ◽  
Adsorption Desorption

TiO2 nanowire arrays in situ grown on Ti foil (TiO2/Ti) were prepared to remove uranium (VI) from aqueous solution. As the Ti foil serves as a carrier for TiO2, the TiO2/Ti adsorbent can be effortlessly retrieved from aqueous solutions by tweezers after adsorption. The presence of TiO2 nanowire arrays on Ti foil was verified by X-ray diffraction and scanning electron microscopy. Parameters in the adsorption process were fully evaluated, including solution pH, contact time, temperature, and uranium (VI) concentration. The adsorption was most efficient in the pH range of 5.0 to 9.0. The maximum uranium (VI) adsorption capacity of TiO2/Ti, based on the Langmuir model, was 354.5 mg g–1 at pH 5.0 and T = 323 K. Thermodynamic parameters showed that the adsorption of uranium (VI) on TiO2/Ti is endothermic and spontaneous. The adsorption capacity of TiO2/Ti remained essentially unchanged after three adsorption–desorption cycles in uranium (VI) solutions. Our results support the application of this adsorbent to removal of uranium (VI) from diversified aqueous samples.

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