Hydroisomerization of n-Pentane on Pt/La Mordenite Prepared by Competitive Cationic Exchange.

Abstract

Pt/La-mordenite catalysts were prepared by competitive cationic exchange for the isomerization of n-paraffins. Four different La/Pt ratios (61, 81, 101 and 111) were employed. La-mordenite was first prepared from its Na-form by three exchange batches with an intermediate calcination, after which the extent of exchange reached 90%. The activity of the prepared catalysts was tested through isomerization of n-pentane in a pulse micro-reactor at 300º–400ºC under atmospheric pressure. Results indicated the increase of isomerization with temperature up to 375ºC, after which it starts to decrease. On the other hand, selectivity decreases due to the continuous increase of cracking with temperature. The catalyst La/Pt ratio showed significant effect on its performance. The best catalyst had a ratio of 101 and exhibited 98% isomerization with respect to thermodynamic equilibrium at 375ºC.