Laminar mesoporous structure of modified montmorillonite clays and its formation mechanism

Abstract

Zr-pillared clays were prepared by heating and ultrasonic methods in intercalation process. The resultants were characterized by XRD, N2 adsorption-desorption, SEM, and TG/DTA analysis. Ultrasonic technology accelerated the pillaring process effectively and obtained better ordered structure than by heating method. The specific surface area and pore volume of the Zr-pillared clays increased by about 13 and 3 times respectively. Rare earth metal (Ce) was introduced into Zr-pillared clays by co-intercalation and dipping method. The specific surface area was increased by co-intercalation approach, but it was decreased dramatically by dipping method. Thermal stability of Ce modified samples prepared by co-intercalation method was enhanced in comparison with Zr-pillared clays. Modification mechanism and “corrugation-like” structural mode of intercalation process was proposed basing on the double XRD peaks in small-angle range of pillared clays, which was related to the deformation of silicate layer.