Propane Aromatization over Pt-Ga/HZSM-5 Catalyst

Direct conversion of propane to aromatics was investigated on Pt/HZSM-5, 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 H-2 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+ and Ga+ causing reduction temperature of Ga sites shifting to a lower temperature and decreases remarkably the amounts of H-2 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 catalysitc stability. Bifunctional roles of Pt and Ga were proposed to understand the catalytic behaviors of Pt-Ga/HZSM-5.