Pillared Clays Prepared from the Reaction of Chromium Acetate with Montmorillonite

Antonio Jimenez-Lopez, Jose Maza-Rodriguez, Pascual Olivera-Pastor, Pedro Maireles-Torres and Enrique Rodriguez-Castellon
Departamento de Química Inorgánica Cristalografía y Mineralogía, Facultad de Ciencias, Universidad de Málaga, Apartado 59, 29071-Málaga, España

Abstract: Refluxing chromium (III) acetate with a Na+-montmorillonite suspension gives rise to the intercalation of linear Cr(III) polyhydroxo-acetate oligomers. Thermally stable chromia pillared montmorillonite materials are obtained upon calcination under ammonia up to 625°C, and basal expansions up to 6 Å are maintained. The porous materials retain high surface areas (366–464 m2 g−1), a micropore volume of 0.1 cm3 g−1 and narrow pore size distributions centered between 7.5 and 12 Å. The most thermally stable materials in air were those prepared under ammonia at 625°C, containing NH4+ as the exchangeable ion.

Key Words: Chromia • Montmorillonite • Pillaring

Clays and Clay Minerals; June 1993 v. 41; no. 3; p. 328-334; DOI: 10.1346/CCMN.1993.0410307
© 1993, The Clay Minerals Society
Clay Minerals Society (www.clays.org)