TPAOH TREATMENT OF HZSM-5 ZEOLITES AND THEIR PROPANE DEHYDROGENATION PERFORMANCE

Abstract

Abstract: HZSM-5 zeolites were treated with different concentrations of TPAOH solutions. Pt/HZSM-5 catalysts were prepared for propane dehydrogenation by loading Pt on HZSM-5 zeolites before and after alkaline treatment. The HZSM-5 samples before and after alkaline treatment were characterized by XRD, SEM, BET, NH3-TPD, H2 chemisorption, FT-IR and TG techniques to investigate the effects of different concentrations of TPAOH solutions on the crystal structure, surface morphology, pore structure, surface acidity. The propane dehydrogenation on Pt/HZSM-5 catalysts was tested. The results showed that the treatment of HZSM-5 by TPAOH solution could effectively introduce mesoporous structure with less influence on the crystal structure and surface morphology of the zeolite, the formation of mesoporous structure is highly adjustable and could modulate the acidity of HZSM-5 zeolites. With the increase of TPAOH concentration, the activity of propane dehydrogenation increases first and then decreases. When the concentration of TPAOH solution is 0.2 mol/L, the initial propane conversion and propene selectivity are 32.7% and 98.6%, respectively.

Key words: TPAOH, HZSM-5, alkali treatment, propane dehydrogenation

CLC Number:

References

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