Optimal Synthesis of Faujasite‐Type Zeolites with a Hierarchical Porosity from Natural Clay
Résumé
Abstract Raw clay, which is an interstratified illite‐kaolinite, has been used as a raw material to prepare Faujasite‐type zeolites. The synthesis was based on the alkaline fusion method followed by hydrothermal treatment without the addition of any extra silica or alumina sources. The effects of various factors on the synthesis process, such as NaOH/clay ratio, crystallization time and temperature, were investigated. The results obtained underlined that these parameters determined whether or not Faujasite‐type zeolites were formed. The optimum synthesis conditions for the synthesis of a single Faujasite zeolite phase were a weight ratio of NaOH/clay of 1.2 fused at 500 °C for 2 h and crystallized at 60 °C for 24 h after homogenization for 12 h. The compounds obtained were characterized by X‐ray diffraction, FTIR spectroscopy, and scanning electron microscopy. Their textural properties were investigated by N 2 adsorption/desorption measurements. The BET surface area of the product synthesized with the optimum conditions was 360 m 2 /g with a relatively high total pore volume of 0.33 m 3 /g. Toluene adsorption on the synthesized trimodal Faujasite zeolite was four times higher than on commercial zeolite. This synthesis is therefore a good way to obtain a cheap and efficient adsorbent for environmental applications.