Synthesis and characterization of nanocrystalline MgAl2O4 spinel via modified sol–gel method

Sanjabi, S.; Obeydavi, Ali

doi:10.1016/j.jallcom.2015.05.107

Cited by 106 publications

(53 citation statements)

References 28 publications

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“…There are several processes to prepare nanocrystalline magnesium aluminate, such as sol-gel [13][14][15][16] , co-precipitation 17 , complexation 1,18 , mechanical milling 3 , mechanical-chemical process 19 , hydrothermal 20 , micro emulsion 21 , combustion method 15,[22][23][24][25][26] and fast pyrolysis 27 . However, many of those are complex, expensive, have several steps, require long time for synthesis, require high temperatures and produce nonhomogeneous and generally low surface area solids 28 .…”

Section: Introductionmentioning

confidence: 99%

Effect of Urea Excess on the Properties of the MgAl2O4 Obtained by Microwave-Assisted Combustion

et al. 2017

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In this paper, magnesium aluminate spinels were prepared by microwave-assisted combustion, using urea as fuel. In order to evaluate the effect of the urea excess used in the synthesis, its mass was added in a range of 1.0 to 2.5 times the stoichiometric amount required. The materials produced were characterized by TGA, FTIR, XRF, XRD, BET, SEM and TEM. The results demonstrated that magnesium aluminate spinel was formed in all solids, but the crystallinity degree and the specific surface area increased according to the amount of urea that was used in the synthesis. The use of excess fuel in the preparation was therefore advantageous, since it eliminated the need of the calcination step, at high temperatures, in order to stabilize the spinel phase and improve the crystallinity of the solid. The heat generated in the combustion process was sufficient to develop the formation of a nanocrystalline structure and produce high purity materials, with a save of 99.4% in energy.

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Section: Introductionmentioning

confidence: 99%

Effect of Urea Excess on the Properties of the MgAl2O4 Obtained by Microwave-Assisted Combustion

et al. 2017

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“…The isotherm was classified as type IV and the hysteresis loop as type H3, both typical of mesoporous structures. 33) The pore sizes of the powders were mostly concentrated at 12 nm, which was similar to the size of the mesoporous MgAl 2 O 4 spinel fibers. Thus, the adsorption performance of the MgAl 2 O 4 spinel powders was measured by the same absorption experiment as shown in Fig.…”

Section: ¹1mentioning

confidence: 61%

Synthesis and adsorption properties of mesoporous MgAl<sub>2</sub>O<sub>4</sub> spinel fibers by coaxial electrospinning

Wei

et al. 2018

J. Ceram. Soc. Japan

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Mesoporous magnesium aluminate (MgAl 2 O 4 ) spinel fibers were prepared using a coaxial electrospinning technique. The phase composition, porous structure and adsorption performance of the mesoporous MgAl 2 O 4 spinel fibers were investigated. Differential thermal/thermo-gravimetric and X-ray-diffraction analysis revealed that gel fibers began to crystallize into the MgAl 2 O 4 spinel phase at 700°C and became fully crystallized at 900°C. The morphology changes in the fibers were tracked by use of a scanning electron microscope and transmission electron microscope, which showed fibers with a mesoporous structure formed at 900°C. The BrunnerEmmet-Teller specific surface area of MgAl 2 O 4 spinel fibers is 36.95 m 2 /g. In addition, the dye adsorption capacity of the fibers shows an adsorption percentage of over 80.0% in 20 mg/l methylene blue after 2 min of adsorption. The kinetic study demonstrated that the adsorption data fit the pseudo-second-order kinetic model more naturally.

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“…In the literature, values of specific surface area of 154 m 2 g -1 (after a calcination at 800 °C) and 52 m 2 g -1 (after a calcination at 900 °C) have been reported. 27 The spinel was doped by wet impregnation method using aqueous solutions of Ce complexes. The Ce 3+ complexes in solution were obtained from different chelating agents and Ce(NO 3 ) 3 .…”

Section: Resultsmentioning

confidence: 99%

CHARACTERIZATION OF CeO2 DOPED MgAl2O4 PREPARED BY THE CHELATING AGENTS-ASSISTED IMPREGNATION METHOD

Villagrán-Olivares¹,

Barroso²,

Abello³

2018

Quim. Nova

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MgAl 2 O 4 spinel employed as support of reforming catalysts was doped by CeO 2 . The samples were prepared by wet impregnation from aqueous solutions of cerium nitrate, with and without chelating agents. The chelating agents used were ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA) and citric acid (CA) at different pH of impregnation. The solids were characterized by TG, XRD, S BET , TPR, SEM-EDX and CO 2 −TPD. Nanoparticles of CeO 2 between 5 and 6.8 nm were obtained by the thermal decomposition in air at 600 °C. The surface cerium reduction occurred in a wide temperature range of 450° to 670 °C. The use of citric acid at pH= 8 led to the lowest crystallite size of CeO 2 and the lowest interaction with the spinel. The H 2 consumption and extent of CeO 2 -support interaction did not show a clear dependence with the CeO 2 crystallite sizes. The use of chelating agents in the impregnation step did not modify the total basicity. Slight changes in the strength of weak basic sites were observed.

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Synthesis and characterization of nanocrystalline MgAl2O4 spinel via modified sol–gel method

Cited by 106 publications

References 28 publications

Effect of Urea Excess on the Properties of the MgAl2O4 Obtained by Microwave-Assisted Combustion

Effect of Urea Excess on the Properties of the MgAl2O4 Obtained by Microwave-Assisted Combustion

Synthesis and adsorption properties of mesoporous MgAl<sub>2</sub>O<sub>4</sub> spinel fibers by coaxial electrospinning

CHARACTERIZATION OF CeO2 DOPED MgAl2O4 PREPARED BY THE CHELATING AGENTS-ASSISTED IMPREGNATION METHOD

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