<abstract xmlns="http://www.w3.org/1999/xhtml">This research concentrated on the structural stability of γ-alumina (γ-Al2O3) was investigated by a combination of differential thermal analysis, X-ray diffractometry and surface-area measurements. The γ –to– θ and then α phase transitions were observed as an exothermic peak at 1000°C–1400°C in the DTA curves. The role of barium oxide as a modifier to stabilize γ-Al2O3 structure has been investigated. XRD measurements show that after calcination at 1000°C for 2 h, a significant fraction of the pure γ-Al2O3 (BaO-free) transformed to θ-Al2O3 while that the transition phase in alumina samples modified by BaO have been reduced significantly. Barium oxide, eliminate pentacoordinated aluminum ions through coordinative saturation and alter these ions into octahedral cations and effectively suppressed the γ –to– α phase transition in Al2O3, which concluded as improving the thermal stability and porous properties of the experimental samples.</abstract>

This research concentrated on the structural stability of γ-alumina (γ-Al2O3) was investigated by a combination of differential thermal analysis, X-ray diffractometry and surface-area measurements. The γ –to– θ and then α phase transitions were observed as an exothermic peak at 1000°C–1400°C in the DTA curves. The role of barium oxide as a modifier to stabilize γ-Al2O3 structure has been investigated. XRD measurements show that after calcination at 1000°C for 2 h, a significant fraction of the pure γ-Al2O3 (BaO-free) transformed to θ-Al2O3 while that the transition phase in alumina samples modified by BaO have been reduced significantly. Barium oxide, eliminate pentacoordinated aluminum ions through coordinative saturation and alter these ions into octahedral cations and effectively suppressed the γ –to– α phase transition in Al2O3, which concluded as improving the thermal stability and porous properties of the experimental samples.

Barium oxide as a modifier to stabilize the γ-Al2O3 structure

Malek-Ashtar University of Technology, Faculty of Chemistry and Chemical Engineering, Tehran,

Polish Journal of Chemical Technology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Barium oxide as a modifier to stabilize the γ-AlO structure

This research concentrated on the structural stability of γ-alumina (γ-Al2O3) was investigated by a combination of differential thermal analysis, X-ray...

Barium oxide as a modifier to stabilize the γ-Al₂O₃ structure

Online veröffentlicht: 30. Dez. 2016

Seitenbereich: 1 - 4

DOI: https://doi.org/10.1515/pjct-2016-0062

Schlüsselwörter
γ-AlO, thermal stability, phase transition, barium oxide, pentacoordinated Al ions

© 2016 Shahram G. Pakdehi et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Barium oxide as a modifier to stabilize the γ-Al2O3 structure

Online veröffentlicht: 30. Dez. 2016

Seitenbereich: 1 - 4

DOI: https://doi.org/10.1515/pjct-2016-0062

Schlüsselwörterγ-AlO, thermal stability, phase transition, barium oxide, pentacoordinated Al ions

© 2016 Shahram G. Pakdehi et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Barium oxide as a modifier to stabilize the γ-Al₂O₃ structure

Schlüsselwörter
γ-AlO, thermal stability, phase transition, barium oxide, pentacoordinated Al ions