Shape Selective Pillared Clay Catalysts for P-Xylene Production

Shape selective xylene production is very important in the polymer industry because of its extensive use as raw material for monomer preparation. The acidity associated with the Lewis and Broensted centers present in the pillars interlayered clay and its textural properties allows good catalytic activity and shape selectivity toward p-xylene production. So, in the present study, ultrasonic and microwave as a new and efficient method was used in the preparation of Co, Cr and ZrO۲-pillared clay with enhanced textural properties, improved thermal stability and significant reduction in processing time. Catalytic alkylation of toluene with methanol was carried out over the prepared catalysts in a catalytic flow system operated under atmospheric pressure at a temperature range ۲۵۰-۴۵۰oC. Results indicated that the pillaring of montmorilonitic clay material with polyoxy-metalic cations (Zr-, Cr- and Co-) improves the texture properties and thermal stability of the obtained catalysts. The Co-PILC catalyst is the most active and selective catalyst towards p-xylene formation, i.e. Co-PILC catalyst is a shape selective for p-xylene formation.