Impact of desilication of BEA zeolites on the catalytic performance in hydroisomerization of n-C^sub 10

Two commercial nanocrystal *BEA zeolites CP811 (P1) and CP814E (P2) with same total Si/Al ratio (Si/Altotal = 12) but different textural properties, were desilicated using different alkaline treatment; classical in presence of NaOH alone, or incorporated with a pore directing agent. P1 was desilicated by NaOH alone, and NaOH + TPABr, while P2 was desilicated in presence of NaOH + TBAOH. A synthesized microcrystal *BEA zeolite with Si/Al total ratio of 36, was also desilicated with NaOH alone, NaOH + TPABr, and NaOH + TBAOH. All parent and desilicated zeolites were transformed into bifunctional catalysts by platinum loading and were tested in the hydroisomerization of n-C10. P1 zeolite was impregnated with different Pt contents to insure maximum activity and selectivity towards isomers products. It has been seen that the improvement of the textural properties by desilication using the different pore directing agents, was not always the cause behind an increase or decrease in the activity and selectivity of the catalyst, but rather was more the location of the Pt particles and their predicted distance from the acidic sites. However, the presence of an interplay between the inter- and intracrystalline mesopores, with the additional parameter of Pt-H+ distance, serve better as combined characteristics behind the final activity and selectivity.