Applied Catalysis A: General, Vol.214, No.2, 229-236, 2001
Effect of Zn loading of the Pt-Zn-HY trifunctional catalysts on the hydroisomerization of n-heptane
The zinc loading needed for having the maximum activity of isomerization, increases with increasing reaction temperature. This means that a stronger cracking activity requires a higher amount of zinc species, the latter being in the cationic form. In the context of the hypothesis of trifunctional catalyst configuration, the new set of results provides another piece of experimental evidence for the desorption-transfer promoting role of the zinc species whose Lewis acid character appears to play an important role in the enhancement of the isomerization activity. Thus, it is possible to achieve higher isomerization performance by using the trifunctional catalysts at lower reaction temperature and longer contact time.
Keywords:n-heptane hydroisomerization;Zn modified Pt-Hy zeolite catalysts;desorption-transfer promoting sites;trifunctional catalysts