Abstract:

 Direct conversion of propane to aromatics was investigated on Pt/HZSM5, Ga/HZSM-5 and Pt-Ga/HZSM-5 catalysts. Platinum introduction into Ga/HZSM-5 resulted in an increase of both the activity and selectivity of propane aromatization. Temperature programmed reduction (TPR) and volumetric chemisorption of H2 have been used to provide insight into the functions of Ga and Pt in Pt-Ga/HZSM-5. Synergistic action of Pt and Ga promotes the reduction of Ga3+ to Ga+ causing reduction temPerature of Ga sites shifting to a lower temperature and decreases remarkably the amounts of H2 adsorbed on Pt sites and thus decreases the ability of alkane hydrogenolysis. It was also found that Pt in Pt-Ga/HZSM-5 plays an important role to improve the catalystic stability. Bifunctional roles of Pt and Ga were proposed to understand catalytic behaviors of Pt-Ga/HZSM-5.

Key words: Propane, Aromatization, Pt-Ga/HZSM-5, TPR, Synergistic bifunctional role, H₂ chemisorption