Main factors controlling the texture of zirconia and alumina pillared clays

The texture development has been studied of a saponite and a montmorillonit e, intercalated with zirconium and aluminum oligomers, after calcination at 773 K. Remarkable differences were observed among the samples, depending o n the source of the intercalating polycations and the parent material. On c alcining, the alumina pillared clays suffered noticeable specific surface a rea and micropore volume losses, which were related to the pillar density o f the samples. On the contrary, the zirconia pillared clays showed a slight surface area increase, which affected both the micropores and the mesopore s and could be due to the combined effect of the thermal decomposition of t he zirconium oligomers and the possible presence of mesoporous ZrO2 particl es. Horvath-Kawazoe and Cheng-Yang methods were both applied in order to ob tain the micropore size distributions of the solids. (C) 2000 Elsevier Scie nce B.V. All rights reserved.