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Bromide-ion distribution in the interlayer of the layered double hydroxides of Zn and Al: Observation of positional disorder

Published online by Cambridge University Press:  01 January 2024

S. V. Prasanna ,
A. V. Radha ,
P. V. Kamath  and
S. Kannan
S. V. Prasanna
Affiliation:
Department of Chemistry, Central College, Bangalore University, Bangalore 560 001, India
A. V. Radha
Affiliation:
Department of Chemistry, Central College, Bangalore University, Bangalore 560 001, India
P. V. Kamath*
Affiliation:
Department of Chemistry, Central College, Bangalore University, Bangalore 560 001, India
S. Kannan
Affiliation:
Discipline of Inorganic Materials and Catalysis, Central Salt and Marine Research Institute (Council of Scientific and Industrial Research), G.B. Marg, Bhavnagar 364 002, India
*
* E-mail address of corresponding author: [email protected]
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Abstract

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Because of the anisotropy in bonding, layered hydroxides crystallize with extensive structural disorder due to the incorporation of stacking faults. In contrast, the loss of crystallinity in Br−-ion intercalated layered double hydroxides (LDHs) arises due to the positional disorder of Br− in the interlayer. The structure of the interlayer in other LDHs is poorly understood due to the low X-ray scattering power of the commonly found anions such as Cl− and NO3−\$\end{document} relative to that of the metal hydroxide layers. On heating to 175°C, the Br− ion migrates from positions of lesser site degeneracy to those of greater site degeneracy as dehydration of the interlayer opens up access to positions hitherto occupied by intercalated water molecules. The new (18h) site is situated closer to the proton of the metal hydroxide layer (1.809 Å) compared to the 6c site (2.402 Å). This shows a pre-association of the bromide ion with the proton of the hydroxide layer leading to the release of HBr upon decomposition of the bromide-containing LDHs. The fact that Cl−-containing LDHs also decompose with the evolution of HCl shows that such a redistribution of the atoms in the interlayer is more common than is generally recognized.

Keywords

Layered Double HydroxidesPositional DisorderThermal Studies
Type
Article
Information
Clays and Clay Minerals , Volume 57 , Issue 1 , February 2009 , pp. 82 - 92
Copyright
Copyright © The Clay Minerals Society 2009

References

Bellotto, M. Rebours, B. Clause, O. Lynch, J. Bazin, D. and Elkaim, E., 1996 A reexamination of hydrotalcite crystal chemistry Journal of Physical Chemistry 100 8527–8534 10.1021/jp960039j.CrossRefGoogle Scholar
Bookin, A.S. and Drits, V.A., 1993 Polytype diversity of the hydrotalcite-like minerals 1. Possible polytypes and their diffraction features Clays and Clay Minerals 41 551–557 10.1346/CCMN.1993.0410504.CrossRefGoogle Scholar
Cavani, F. Trifiro, F. and Vaccari, A., 1991 Hydrotalcite-type anionic clays: preparation, properties and applications Catalysis Today 11 173–301 10.1016/0920-5861(91)80068-K.CrossRefGoogle Scholar
De Roy, A., Forano, C., and Besse, J.P. (2001) Layered Double Hydroxides: Past and Future (Rives, V., editor). Nova Science, New York, pp. 1–37.Google Scholar
Del Hoyo, C., 2007 Layered double hydroxides and human health: An overview Applied Clay Science 36 103–121 10.1016/j.clay.2006.06.010.CrossRefGoogle Scholar
Ennadi, A. Legrouri, A. De Roy, A. and Besse, J.P., 2000 X-ray diffraction pattern simulation for thermally treated [Zn-Al-Cl] layered double hydroxide Journal of Solid State Chemistry 152 568–572 10.1006/jssc.2000.8740.CrossRefGoogle Scholar
Kameda, T. Yoshioka, T. Watanabe, K. Uchida, M. and Okuwaki, A., 2007 Dehydrochlorination behavior of a chloride ion-intercalated hydrotalcite-like compound during thermal decomposition Applied Clay Science 35 173–179 10.1016/j.clay.2006.08.010.CrossRefGoogle Scholar
Oesten, R. and Böhm, H., 1993 Ionic mobility in basic double salts. Part 1: Hydrotalcites Solid State Ionics 62 199–204 10.1016/0167-2738(93)90373-B.CrossRefGoogle Scholar
Prasanna, S.V. Rao, R.A.P. and Kamath, P.V., 2006 Layered double hydroxides as potential chromate scavengers Journal of Colloid and Interface Science 304 292–299 10.1016/j.jcis.2006.08.064.CrossRefGoogle ScholarPubMed
Prasanna, S.V. Kamath, P.V. and Shivakumara, C., 2007 Synthesis and characterization of Chromate intercalated layered double hydroxides Materials Research Bulletin 42 1028–1309 10.1016/j.materresbull.2006.09.021.CrossRefGoogle Scholar
Radha, A.V. Shivakumara, C. and Kamath, P.V., 2005 DIFFaX simulations of stacking faults in layered double hydroxides (LDHs) Clays and Clay Minerals 53 521–528 10.1346/CCMN.2005.0530508.CrossRefGoogle Scholar
Radha, A.V. Kamath, P.V. and Shivakumara, C., 2007 Conservation of order, disorder and crystallinity during anion exchange reactions among layered double hydroxides (LDHs) of Zn with Al Journal of Physical Chemistry B 111 3411–3418 10.1021/jp0684170.CrossRefGoogle ScholarPubMed
Reddy, M.K.R. Xu, Z.P. Lu, G.Q. and da Costa, J.C.D., 2006 Layered double hydroxide for CO2 capture: Structure evolution and regeneration Industrial and Engineering Chemistry Research 45 7504–7509 10.1021/ie060757k.CrossRefGoogle Scholar
Rodriguez-Carvajal, J. Full Prof 2000 Laboratoire Léon Brillouin (UMR12 CEA-NRS): Gif-sur-Yvette Cedex, France, available at (accessed February 2007).Google Scholar
Roussel, H. Briois, V. Elkaïm, E. de Roy, A. and Besse, J.P., 2000 Cationic order and structure of [Zn-Cr-Cl] and [Cu-Cr-Cl] layered double hydroxides: an XRD and EXAFS study Journal of Physical Chemistry B 104 5915–5923 10.1021/jp0000735.CrossRefGoogle Scholar
Sels, B.F. De Vos, D.E. and Jacobs, P.A., 2001 Hydrotalcite-like anionic clays in catalytic organic reactions Catalysis Reviews 43 443–488 10.1081/CR-120001809.CrossRefGoogle Scholar
Thomas, G.S. and Kamath, P.V., 2006 Line broadening in the PXRD patterns of layered hydroxides: The relative effects of crystallite size and structural disorder Journal of Chemical Science 118 127–133 10.1007/BF02708774.CrossRefGoogle Scholar
Thomas, G.S. Rajamathi, M. and Kamath, P.V., 2004 DIFFaX simulations of polytypism and disorder in hydrotalcite Clays and Clay Minerals 52 693–699 10.1346/CCMN.2004.0520603.CrossRefGoogle Scholar
Thomas, G.S. Radha, A.V. Vishnu Kamath, P. and Kannan, S., 2006 Thermally induced polytype transformations among the layered double hydroxides (LDHs) of Mg and Zn with Al Journal of Physical Chemistry B 110 12365–12371 10.1021/jp061377f.CrossRefGoogle ScholarPubMed
Treacy, M.M.J. Newsam, J.M. and Deem, M.W., 1991 A general recursion method for calculating diffracted intensities from crystals containing planar faults Proceedings of Royal Society, London A433 499–520 10.1098/rspa.1991.0062.Google Scholar