Non-aggressive way using zirconium acetate for preparation of zirconium pillared clay developing high sulfur thermal stability over 830 °C

Abstract

Pillared zirconium clay modified by sulfate constitutes a new class of materials. Nevertheless, the classical procedure consisting of impregnating these solids with sulfate solutions presents some disadvantages such as low surface area and a poor sulfur thermal stability. In a previous work, we have developed a new in situ sulfation preparation method using zirconyl chloride as zirconium precursor. However, the use of this salt gives an intercalation solution with a very low pH which can affect the clay layers. Furthermore, the addition of sulfate ions to the ZrO2 solution is limited by Hauser salt or polymeric phase precipitation. In this work, zirconium acetate solution was used in order to increase the pH of the pillaring solution and the content of sulfate ions introduced. Different preparation parameters and their effect on the structural and textural properties have been investigated. The resulting materials present a best zirconium-sulfate intercalation with higher sulfate rate and develop very high thermal stability of sulfur even at about 830 ~