QUT ePrints

Thermal decomposition of synthesized layered double hydroxides based upon Mg/(Fe,Cr) and carbonate

Spratt, Henry J., Palmer, Sara J., & Frost, Ray L. (2008) Thermal decomposition of synthesized layered double hydroxides based upon Mg/(Fe,Cr) and carbonate. Thermochimica Acta, 479(1-2), pp. 1-6.

View at publisher

Abstract

Thermal analysis complimented with evolved gas mass spectrometry has been applied to hydrotalcites of the pyroaurite-stitchtite series containing the carbonate anion prepared by co-precipitation and with varying Fe3+,Cr3+ trivalent cation ratio. The resulting materials were characterized by XRD, and TGA/DTG to determine the stability of the hydrotalcites synthesised. Hydrotalcites of formula Mg6(Cr0.8,Fe0.2)2(OH)16(CO3).xH2O, Mg6(Cr0.6,Fe0.4)2(OH)16(CO3).xH2O, Mg6(Cr0.4,Fe0.6)2(OH)16(CO3).xH2O and Mg6(Cr0.2,Fe0.8)2(OH)16(CO3).xH2O formed by intercalation with the carbonate anion as a function of Fe3+,Cr3+ trivalent cationic ratio show variation in the d-spacing attributed to the size of the cation.

The thermal decomposition of stitchtite-pyroaurite solid solution

a) removal of adsorbed water (< 100 degrees Celsius),

b) elimination of the interlayer structural water (100 – 150 degrees Celsius), and

c) the simultaneous dehydroxylation and decarbonation of the hydrotalcite framework (300 – 400 degrees Celsius).

The effect of replacement of Cr3+ by Fe3+ has no effect on the dehydroxylation temperature. The ion current curves provide evidence for the formation of Fe3+ and Cr3+ carbonates during dehydroxylation. Dehydroxylation results in the collapse of the hydrotalcite structure to that of its corresponding metal oxides, and results in the formation of spinels, including MgO, MgFe2O4, MgCr2O4, and MgFeAlO4.

Impact and interest:

11 citations in Scopus
Search Google Scholar™
10 citations in Web of Science®

Citation countsare sourced monthly from Scopus and Web of Science® citation databases.

These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.

Citations counts from the Google Scholar™ indexing service can be viewed at the linked Google Scholar™ search.

Full-text downloads:

221 since deposited on 17 Oct 2008
53 in the past twelve months

Full-text downloadsdisplays the total number of times this work’s files (e.g., a PDF) have been downloaded from QUT ePrints as well as the number of downloads in the previous 365 days. The count includes downloads for all files if a work has more than one.

ID Code: 15227
Item Type: Journal Article
Keywords: hydrotalcite, stitchtite, pyroaurite, carbonate, X, ray Diffraction, thermal analysis
DOI: 10.1016/j.tca.2008.08.016
ISSN: 0040-6031
Subjects: Australian and New Zealand Standard Research Classification > CHEMICAL SCIENCE (030000) > PHYSICAL CHEMISTRY (INCL. STRUCTURAL) (030600)
Australian and New Zealand Standard Research Classification > CHEMICAL SCIENCE (030000) > PHYSICAL CHEMISTRY (INCL. STRUCTURAL) (030600) > Catalysis and Mechanisms of Reactions (030601)
Australian and New Zealand Standard Research Classification > CHEMICAL SCIENCE (030000) > PHYSICAL CHEMISTRY (INCL. STRUCTURAL) (030600) > Colloid and Surface Chemistry (030603)
Divisions: Past > QUT Faculties & Divisions > Faculty of Science and Technology
Current > QUT Faculties and Divisions > Science & Engineering Faculty
Copyright Owner: Copyright 2008 Elsevier
Copyright Statement: Reproduced in accordance with the copyright policy of the publisher.
Deposited On: 17 Oct 2008
Last Modified: 06 May 2014 09:44

Export: EndNote | Dublin Core | BibTeX

Repository Staff Only: item control page