(491c) A Comparative Study of N-Octane Aromatization over Modified Mfi- and Mel-Type Zeolite Catalysts

The aromatization of n-octane was studied over modified MFI-(ZSM-5) and MEL-(ZSM-11) type zeolite catalysts as bifunctional catalysts to investigate the effect of pore geometry on their catalytic activity and product distribution. ZSM-5 and ZSM-11 zeolites were synthesized by the conventional method and characterized by using XRD, SEM, and surface area analyzer. Zinc was loaded into the synthesized zeolites by ion exchange to prepare Zn/HZSM-5 and Zn/HZSM-11 catalysts which were then tested for aromatization at 500ºC under atmospheric pressure. Preliminary results revealed that Zn loaded into both zeolites provided a significant increase in total aromatics selectivity. The n-octane aromatization activity for such catalysts was found in the order of Zn/HZSM-5 > Zn/HZSM-11 > HZSM-5 > HZSM-11. This suggests that the aromatization of n-octane takes place preferentially in zigzag channels of ZSM-5 more than in straight channels of ZSM-11. Toluene was observed as a major product, followed by C8-aromatics and benzene on all the catalysts tested.