Synthesis and characterization of delaminated iron-pillared clay with meso–microporous structure

In the present work, iron pillared clays were synthesized by the reaction of montmorillonite with base-hydrolyzed solutions of Fe(III) nitrate. In contrast with the classical microporous pillared structure, a novel meso–microporous delaminated structure containing pillared fragments in iron-pillared clay was obtained. A considerable amount of NO3- is found to be retained in the resultant delaminated iron-pillared clays even after thorough washing by successive agitations/centrifugations. This amount is closely related with the content of the iron species in the iron-pillared clays. The highest BET specific surface area and the largest porosity of the delaminated iron pillared clays are 215.7 m2/g and 0.29 ml/g, respectively. Mesopores in the delaminated structure make the main contribution to the total surface area and porosity, and most of them are preserved after calcination at 773 K. These fundamental results are of importance in developing novel heterogeneous catalysts and adsorbents.