Preparation of Al2O3 Supports for Thin Membrane Fabrication

Topuz, Berna; Yurttaş, Ali Semih; Altunsoy, Ali

doi:10.18596/jotcsa.351708

Cited by 2 publications

(1 citation statement)

References 19 publications

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“…Ten years later, Wang et al investigated photoluminescence in their porous monolithic α-Al 2 O 3 prepared by a modified polyacrylamide gel route, finding pore diameters of 80-500 nm [83]. Topuz et al reported pore diameters of 110 nm in macroporous α -alumina supports prepared by using vacuum assisted filtration of α-Al 2 O 3 suspensions [174]. Finally, three articles were published in 2019: Ahmad et al reported on α-Al 2 O 3 from hydrothermally prepared ammonium aluminum carbonate hydroxide whiskers with distinct pore diameters of 260 nm, yet without precisely determining the corresponding pore volume [41].…”

Section: Pure α-Alumina With Pores In the Sub-micrometer Rangementioning

confidence: 99%

Towards Macroporous α-Al2O3—Routes, Possibilities and Limitations

2020

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This article combines a systematic literature review on the fabrication of macroporous α-Al2O3 with increased specific surface area with recent results from our group. Publications claiming the fabrication of α-Al2O3 with high specific surface areas (HSSA) are comprehensively assessed and critically reviewed. An account of all major routes towards HSSA α-Al2O3 is given, including hydrothermal methods, pore protection approaches, dopants, anodically oxidized alumina membranes, and sol-gel syntheses. Furthermore, limitations of these routes are disclosed, as thermodynamic calculations suggest that γ-Al2O3 may be the more stable alumina modification for ABET > 175 m2/g. In fact, the highest specific surface area unobjectionably reported to date for α-Al2O3 amounts to 16–24 m2/g and was attained via a sol-gel process. In a second part, we report on some of our own results, including a novel sol-gel synthesis, designated as mutual cross-hydrolysis. Besides, the Mn-assisted α-transition appears to be a promising approach for some alumina materials, whereas pore protection by carbon filling kinetically inhibits the formation of α-Al2O3 seeds. These experimental results are substantiated by attempts to theoretically calculate and predict the specific surface areas of both porous materials and nanopowders.

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Section: Pure α-Alumina With Pores In the Sub-micrometer Rangementioning

confidence: 99%