Calcination products of gibbsite studied by X-ray diffraction, XPS and solid-state NMR

A. Malki, Z. Mekhalif, S. Detriche, G. Fonder, A. Boumaza, A. Djelloul

Research output: Contribution to journalArticle

Abstract

The changes caused by heat treatment of gibbsite powder at 300-1473 K were studied using the X-ray diffraction (XRD), X-ray photoemission (XPS) spectra and 27Al magic angle spinning nuclear magnetic resonance spectroscopy (27Al MAS NMR). XRD analysis indicates that the transformation sequence involves the formation of κ-Al2O3 as an intermediate phase between χ- and α-Al2O3. The crystallite size of χ-Al2O3 is as small as 10 nm. XPS analysis indicates that the ratio of aluminium atoms to oxygen atoms in χ-Al2O3 and κ-Al2O3 increases, whereas the expected ratio is observed in α-Al 2O3. The percentage of AlO4 units in the transition aluminas follows the same behaviour as the ratio of Al/O.

Original languageEnglish
Pages (from-to)8-15
Number of pages8
JournalJournal of Solid State Chemistry
Volume215
DOIs
Publication statusPublished - 1 Jan 2014

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Keywords

  • Gibbsite
  • Transition alumina
  • X-ray diffraction
  • X-ray photoelectron microscopy

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