Isomerization of n-hexane on Highlydispersed Pt- and Pd Catalysts
N.A. Zakarina, M.K. Shaymerdenova, G.V. Akulova and A.M.Autanov
D.V. Sokolskii Institute of Organic Catalysis and Electrochemistry ME&S RK, 142, Kunaev Str., 480100 Almaty, Kazakhstan
The influence of zeolite nature (Y, ZSM-5) and silicoalumophosphates (SAPO-5 and SAPO-11) in composition of Pt-, Pd- and Pt-Pd-catalysts, supported on natural clays (clinoptillolite, montmorillonite) on direction of n-hexane conversion in hydrogen environment was investigated. The introduction of activated clays into metal containing zeolite catalysts makes it possible to form the defined porous structure possessing high durability and thermal stability. It was shown that correlation of isomerization and hydrocracking products is defined by acidic characteristics of catalysts and also dispersion of metallic component and pores size of initial zeolite or silicoalumophosphate. The distribution of acidic sites in a zeolite containing catalysts synthesized in the same way and with the same compound depends on the nature of matrix and the way of its activation.
It was shown that the bimolecular mechanism of n-butane conversion predominates on Pt/ZSM-catalysts, and n-hexane conversion proceeds primarily by monomolecular mechanism with the formation of isohexanes on catalysts with zeolite Y and SAPO-5 and SAPO-11.