Novel eco-friendly method for preparation of mesoporous alumina from the product of rapid thermal treatment of gibbsite

In this paper, the thermal decomposition of crystalline Al(OH)3 was studied over the temperature range of 260–400 °C for particles with a size between 10 and 150 µm. The weight losses and thermal effects occurring in each of the dehydration process were assessed using thermogravimetry (TG) and differential scanning calorimetry (DSC) thermal analysis. X-ray diffraction (XRD) patterns, refined by the Rietveld method, were used for mineral phase identification, phase composition analysis, and crystallinity degree determination. Moreover, the particle size distributions and their corresponding D10, D50, and D90 numeric values were determined with a laser analyzer. We observed a strong relationship between the calcination temperature, the initial gibbsite grade particle size, and the crystallinity of the resulting powders. Hence, for all endothermic effects identified by DSC, the associated temperature values significantly decreased insofar as the particle dimensions decreased. When the gibbsite was calcined at a low temperature, we identified small amounts of boehmite phase along with amorphous new phases and unconverted gibbsite, while the powders calcined at 400 °C gradually yielded a mixture of boehmite and crystalized γ-Al2O3. The crystallinity % of all phase transition products declined with the increase in particle size or temperature for all the samples.

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“…All our results are in good agreement with best approaches to the subject found in the literature [66][67][68][69][70][71][72].…”

Section: Gdah-05supporting

confidence: 91%

Thermally Activated Al(OH)3 Part II—Effect of Different Thermal Treatments

Vasile

Dobra²,

Iliev

et al. 2021

Ceramics

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“…Nitrogen sorption isotherms of Z‐based samples belong to II type with a mild H3 hysteresis loop, which is characteristic of slit‐shaped and wedge‐like mesopores formed by the aggregation of needle zeolite crystals. There were expected changes in the isotherms for the composite support (ZA), due to the contribution from the γ‐alumina binder, which has a fiber morphology [24] . Regardless of the support (Z or ZA), neither the addition of Mg nor the method of promoting appreciably affected the structure of mesopores; the difference in size‐distributions of mesopores for initial and Mg‐containing samples was of the same order as for samples upon repeated testing.…”

Section: Resultsmentioning

confidence: 98%

“…There were expected changes in the isotherms for the composite support (ZA), due to the contribution from the γ-alumina binder, which has a fiber morphology. [24] Regardless of the support (Z or ZA), neither the addition of Mg nor the method of promoting appreciably affected the structure of mesopores; the difference in sizedistributions of mesopores for initial and Mg-containing samples was of the same order as for samples upon repeated testing. One can find examples of the isotherms, t-plots, and pore-size distributions in Figure S4 and Figure S5.…”

Section: Structural and Textural Properties Of The Samplesmentioning

confidence: 92%

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Characterization and Hydroisomerization Performance of Mg‐Promoted, Pt/ZSM‐23‐Based Catalysts

et al. 2022

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The effect of Mg on the acidic and metal functions in Pt/ZSM‐23 catalysts has been studied, using both pure zeolite (Z) and preshaped ZSM‐23/Al2O3 composite (ZA) and varying the content and method of Mg loading. N2 physisorption, CO chemisorption, H2/O2 titration, XRD, TEM, TPR, and FTIR were employed to characterize the phase composition, textural and acidic properties, platinum location and dispersion. The shaping procedure used left the acidity of the parent zeolite virtually intact, while Pt dispersion on the composite support was greatly increased. Despite the increased CPt/CH+ ratio, the Pt/ZA catalyst underperformed Pt/Z in the yield of branched isomers produced in n‐decane hydroconversion. Irrespective of the support, its impregnation with Mg allowed tuning the surface acidity and improving the isomerization selectivity above the level characteristic of unpromoted Pt/Z. However, the addition of Mg through ion‐exchange resulted in an opposite effect on the catalyst selectivity. Possible reasons of such a complex behavior are discussed.

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“…The dispersion of the active phase and the interactiondeterioration with the support are promoted by the chelating agents present,such as citric acidandother organic complexing agents and acid additives, such as boron and phosphorus [34,35,36].…”

Section: Catalystmentioning

confidence: 99%

Difficulties in the industrial introduction of new effective hydrodesulfurization catalysts in the Russian Federation

Konoplin

Кондрашева

2021

E3S Web Conf.

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The article presents bibliographic knowledgeof the world-scaleinventions that formed the basis ofHDS-catalysts for the development of variousoil products. Extensive studies were conductedon optimizationof carrier properties, active-phase chemical-mass composition, and basictech-nological parameters of transformation of initial components into active six-sided MoS2 groups which are decorated by CoS2 molecules, involving stages of desulfurization ofoxide formsof the catalyst. Differences in the microstructure of Al2O3supportsderived from aluminum hydroxide of vari-ous genesis are described. Comparative possibilitiesof binding properties of aluminum hydroxide raw materials in laboratory tests and molding of-waterpeptidized pastesare presented.

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Novel eco-friendly method for preparation of mesoporous alumina from the product of rapid thermal treatment of gibbsite

Cited by 33 publications

References 22 publications

Thermally Activated Al(OH)3 Part II—Effect of Different Thermal Treatments

Thermally Activated Al(OH)3 Part II—Effect of Different Thermal Treatments

Characterization and Hydroisomerization Performance of Mg‐Promoted, Pt/ZSM‐23‐Based Catalysts

Difficulties in the industrial introduction of new effective hydrodesulfurization catalysts in the Russian Federation

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