Journal ArticleDOI
Transition alumina phases induced by heat treatment of boehmite: An X-ray diffraction and infrared spectroscopy study
A. Boumaza,L. Favaro,Jean Lédion,Gaël Sattonnay,J.-B. Brubach,P. Berthet,A. M. Huntz,Pascale Roy,Robert Tétot +8 more
TLDR
In this article, the gamma, delta, theta and alpha-Al{sub 2}O{sub 3} phases, prepared by dehydration of aluminium oxihydroxide AlOOH (boehmite), were measured by XRD and IR spectroscopy on all samples.Citations
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The surface of transitional aluminas: A critical review
TL;DR: The data reported in the literature concerning the structure, the morphology and porosity, the physicochemical properties and the surface properties of transitional aluminas are reviewed critically in this article, where the authors discuss the nature and assignment of the OH stretching bands associated to surface hydroxyl groups and the nature of the surface acidity and basicity.
Journal ArticleDOI
Catalytic hydrotreatment of fast-pyrolysis oil using non-sulfided bimetallic Ni-Cu catalysts on a delta-Al2O3 support
Agnes Retno Ardiyanti,S. A. Khromova,Robertus Hendrikus Venderbosch,Vadim A. Yakovlev,Hero J. Heeres +4 more
TL;DR: In this paper, the catalytic hydrotreatment of fast pyrolysis oil using bimetallic NiCu/delta-Al(2)o(3) catalysts with various Ni/Cu ratios (0.32 to 8.1 w/w) at a fixed total metal intake of about 20 wt% with the objective to improve product properties for co-feeding applications in conventional oil refineries.
Journal ArticleDOI
Nanoengineering Super Heat-Resistant, Strong Alumina Aerogels
TL;DR: In this paper, a novel acetone-aniline in situ water formation (ISWF) method combined with novel modification techniques: supercritical fluid modification (SCFM) and hexamethyldisilazane gas phase modification was used to enhance the heat resistance of alumina aerogel.
Journal ArticleDOI
XPS, FTIR, EDX, and XRD Analysis of Al2O3 Scales Grown on PM2000 Alloy
TL;DR: In this paper, the results obtained after calcination of Al2O3 hydroxides and oxidation of alumino-formers alloys were compared with those known from the literature about calcination.
Journal ArticleDOI
Control of the γ-alumina to α-alumina phase transformation for an optimized alumina densification
Samir Lamouri,M. Hamidouche,N. Bouaouadja,Houcine Belhouchet,Vincent Garnier,Gilbert Fantozzi,Jean François Trelkat +6 more
TL;DR: In this article, the influence of the heating rate on densification and microstructural evolution of transition alumina was studied by in situ X-rays diffraction from the ambient to 1200°C, and it was shown that low heating rate leads to a significant reduction of the temperature of the α-Al 2 O 3 alumina formation.
References
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Journal ArticleDOI
Study of phase transformations during calcination of aluminum hydroxides by selected area electron diffraction
B.C. Lippens,J.H. de Boer +1 more
TL;DR: In this paper, the formation of the well ordered super spinel structure is suppressed by obstructing the diffusion of the A1 ions either by the surface of numerous pores or by incorporating large ions such as Na ions (y-alumina from crystalline boehmite) and in these cases the disordered spinel type aluminas are transformed at a high temperature to 0and a-Al~O 3 by complete recrystallization to small particles which still have some preferred orientation.
Journal ArticleDOI
Infrared Lattice Vibrations and Dielectric Dispersion in Corundum
TL;DR: In this article, room-temperature reflectivity measurements in the wavelength range 1 to 140 µm on corundum and ruby have been made, and a classical oscillator analysis of the data shows that the optical lattice modes with dipole moment vibrating perpendicular to the $C$ axis occur at 15.7, 17.4, 22.6, 26.0, and 25.0 µm.
Journal ArticleDOI
A kinetic study of the system γ-AlOOHAl2O3
S.J. Wilson,J.D.C. Mc Connell +1 more
TL;DR: In this paper, a time-temperature study of the system γ-AlOOH (boehmite) Al 2 O 3 has been made, and the TTT diagram produced demonstrates the course of the transformation sequence which involves a number of metastable transition alumina intermediate phases.
Journal ArticleDOI
Determination of the structure of y-alumina from interatomic potential and first principles calculations: The requirement of significant numbers of nonspinel positions to achieve an accurate structural model
TL;DR: In this paper, the authors performed an extensive computational study of {gamma}-Al{sub 2}O{sub 3, and found that on average over 40% of the cations in the structure occupied nonspinel positions, and approximately two-thirds of these occupied c symmetry positions.
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