STUDY ON Pt/Hβ HYDROISOMERIZATION CATALYST AND ITS REDUCTION CONDITIONS

Abstract

Abstract: The Pt/Hβ isomerization catalysts were prepared by using Hβ zeolite with different silica-alumina ratio as the carrier and loaded with Pt. The Pt/Hβ catalysts were characterized by N2 adsorption-desorption，XRD，NH3-TPD，Py-IR and TEM. And the isomerization performance of the prepared catalysts was evaluated in a 10 mL fixed-bed micro-reactor. The results showed that the silica-alumina ratio of Hβ zeolite has a significant effect on the acidity and pore structure of the catalyst. With the increase of silica-alumina ratio，while the total acid，medium strong acid and Br?nsted acid sites, and the specific surface area and pore volume decrease，which improve the conversion rate of n-hexane and inhibit the isomerization and dimethylbutane selectivity. The Pt/Hβ catalyst with silica-alumina ratio of 25 has the best isomerization performance. Reduction temperature and pressure mainly affects the size and distribution of Pt on the catalyst. At reduction temperature of 350 ℃ and 0.75 MPa，the average particle size of Pt is the smallest and uniformly distributed，which is beneficial to improve the metallicity and acid matching degree of the catalysts，and the best isomerization results is 81.16% n-hexane conversion rate，82.89% isomerization rate，25.58% dimethylbutane selectivity.

Key words: Pt/Hβ, hexane, isomerization, reduction conditions

CLC Number:

References

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