Study of the hydrolysis of combined Al3+ and Ga3+ aqueous solutions: Formation of an extremely stable GaO4Al12(OH)24(H2O) polyoxycation

✍ Scribed by Susan M. Bradley; Ronald A. Kydd; Raghav Yamdagni

• Publisher: John Wiley and Sons
• Year: 1990
• Tongue: English
• Weight: 429 KB
• Volume: 28
• Category: Article
• ISSN: 0749-1581
• DOI: 10.1002/mrc.1260280903

✦ Synopsis

Abstract

^71^Ga and ^27^Al NMR and clay mineral pillaring studies were used to investigate the hydrolysis of Al(H~2~O)–Ga(H~2~O) solutions, mixed in an Al:Ga mole ratio of 12:1, and confirmed the formation of the previously proposed GaO~4~Al~12~(OH)~24~(H~2~O) polyoxycation. This species has been found to be formed in marked preference to both AlO~4~Al~12~(OH)~24~(H~2~O) and the previously identified GaO~4~Ga~12~(OH)~24~(H~2~O) ions, and further to have a much higher thermal stability in solution than either of these. It is suggested that the reason for the increased stability of the ‘GaAl~12~’ species is that the substitution of a larger metal into the central tetrahedral position has resulted in the formation of a less distorted structure.