Polymeric hydroxy-Al cations were introduced into the interlayer of acid-activated montmorillonites by cation exchange. The resulting pillared materials possessed layer spacings of 18 – 20 Å, surface areas between 250 – 320 m2/g, pore volumes in the range 0.3 – 0.38 cc/g and pore diameters in the range 32 – 40 Å depending on preparation procedures (i.e pillaring temperature and drying method). Powder XRD analysis indicated that the pillars formed were stable to temperatures above 500 °C. The surface acidity of these type of pillared clays was higher than that of pillared non-activated clays. Preliminary studies on their adsorption capacity for chlorophyll showed that they were superior to pillared non-activated clays.