Reversible thermal behavior of the layered double hydroxides (LDHs) of Mg with Ga and In

Journal Article · Wed Apr 20 04:00:00 EDT 2005 · Materials Research Bulletin

DOI:https://doi.org/10.1016/j.materresbull.2004.12.011· OSTI ID:20889761

Thomas, Grace S ^[1]; Kamath, P Vishnu ^[1]

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1. Department of Chemistry, Central College, Bangalore University, Bangalore 560001 (India)

The layered double hydroxides (LDHs) of Mg with Ga and In decompose completely on heating to 500 deg. C to yield poorly ordered oxide residues. In the Mg-Ga system, the oxide residue has a rock-salt structure with Ga incorporated in the MgO matrix. In the Mg-In system, the oxide residue is X-ray amorphous. These oxide residues revert back to the original LDH either on standing in a water-saturated atmosphere or on hydrothermal treatment in a Na{sub 2}CO{sub 3} solution. In contrast, the LDHs of Co with Ga and In yield the thermodynamically stable spinel oxides and the decomposition is irreversible. These results have implications for the synthesis of 'oxide' catalysts by thermal decomposition of the LDHs.

• OSTI ID: 20889761
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: 4 Vol. 40; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CATALYSTS
HEATING
HYDROXIDES
MAGNESIUM OXIDES
PYROLYSIS
RESIDUES
SALT DEPOSITS
SODIUM CARBONATES
SPINELS
THERMAL GRAVIMETRIC ANALYSIS
X RADIATION
X-RAY DIFFRACTION