Wasteless Synthesis and Properties of Highly Dispersed MgAl2O4 Based on Product of Thermal Activation of Gibbsite Full article
| Journal |
Chemistry
, E-ISSN: 2624-8549 |
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| Output data | Year: 2022, Volume: 4, Number: 2, Pages: 316-328 Pages count : 13 DOI: 10.3390/chemistry4020024 | ||
| Tags | MgAl2O4; wasteless synthesis; texture; surface acidity | ||
| Authors |
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| Affiliations |
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Funding (1)
| 1 | Ministry of Science and Higher Education of the Russian Federation | 0239-2021-0004 |
Abstract:
The study showed that the interaction of the product of centrifugal thermal activation of gibbsite with an aqueous solution of magnesium nitrate at a cationic ratio Mg:Al = 1:2 leads to the formation of mixed double hydroxides both under hydrothermal treatment at 150 C and at room temperature. The subsequent thermal treatment at 550 C of the product of mild interaction leads to ~90% alumina-magnesia spinel and ~10% MgO, while the treatment of the hydrothermal interaction product leads to ~100% spinel with the stoichiometric composition MgAl2O4. The obtained spinel samples possess a high specific surface area (above 100 m2/g) and a hierarchical pore structure formed by the micron-level particles of different sizes (1–2 and 10–20 μm) consisting of ~70 nm crystallites with ~3 nm pores; the samples differ mostly in the total volume and quantitative ratio of
the pores. The samples have Lewis acid sites of moderate strength on the surface, the amount of which is much lower to how it is when compared with a sample prepared by precipitation in that they also differ by quantity from each other as well (503 μmol/g for stoichiometric spinel and 304 μmol/g for sample with admixture of MgO). As the calcination temperature is raised to 850 C, the acidity decreases—only weak Lewis acid sites are observed, the amount of which is also higher for stoichiometric spinel (161 and 39 μmol/g, respectively). The method proposed for the synthesis of alumina-magnesia systems provides a high dispersion and a much lower surface acidity for the oxides; in addition, it minimizes or completely excludes wash water, in distinction to the precipitation method.
Cite:
Zhuzhgov A.V.
, Kruglyakov V.Y.
, Glazneva T.S.
, Suprun E.A.
, Isupova L.A.
Wasteless Synthesis and Properties of Highly Dispersed MgAl2O4 Based on Product of Thermal Activation of Gibbsite
Chemistry. 2022. V.4. N2. P.316-328. DOI: 10.3390/chemistry4020024 WOS Scopus РИНЦ AN OpenAlex
Wasteless Synthesis and Properties of Highly Dispersed MgAl2O4 Based on Product of Thermal Activation of Gibbsite
Chemistry. 2022. V.4. N2. P.316-328. DOI: 10.3390/chemistry4020024 WOS Scopus РИНЦ AN OpenAlex
Dates:
| Submitted: | Mar 18, 2022 |
| Accepted: | Apr 9, 2022 |
| Published online: | Apr 11, 2022 |
| Published print: | Jun 1, 2022 |
Identifiers:
| Web of science: | WOS:000816323200001 |
| Scopus: | 2-s2.0-85130292646 |
| Elibrary: | 48585596 |
| Chemical Abstracts: | 2022:1631953 |
| OpenAlex: | W4223655040 |