The micropores of the EUO zeolite consist of 10-membered ring (10-MR)
channels with deep side-pockets circumscribed by 12-MRs. In decane iso
merization and hydrocracking EUO zeolites crystallized in the presence
of hexamethonium (HM) and dibenzyldimethylammonium (DBDMA) exhibit di
fferent molecular shape selective properties. The catalytic sites of E
UO specimens crystallized with DBDMA are located in more spacious cavi
ties than those of EUO crystals synthesized with HM. This disparity in
molecular shape selectivity is explained by a different location of t
he framework aluminium atoms in the two materials, viz. by the absence
of aluminium in the 10-MR channels in EUO-DBDMA. Such aluminium sitin
g is in agreement with the location of the organic template cations in
the pores of the as-synthesized zeolites suggested in literature and
revealed by a molecular graphics modeling.