CHARACTERIZATION OF THE PORE GEOMETRY OF THE HIGH-SILICA ZEOLITE NCL-1 THROUGH VARIOUS CATALYTIC TEST REACTIONS

The effective void space and pore geometry of the new high-silica zeolite NCL-1 have been characterized through the constraint index (CI = 1.0 at 523 K); n-decane conversion [refined constraint index = 1.8; methylnonanes ethyloctanes = 96:4 at 5% Y(iso); monobranched dibranched = 70:30 at maximum Y(iso) (almost-equal-to 65%); moles of isopentane almost-equal-to 47.5 at almost-equal-to 35% Y(cr); n-propylheptane = 0.9% (among monobranched isomers at maximum isomerization conversion) and negligible secondary hydrocracking]; the spaciousness index (SI = 6.6) and m-xylene conversion [p/o almost-equal-to 1.1; log(isomerization/disproportionation) almost-equal-to 1; 1,3,5/1,2,4-trimethylbenzene = 0.1; 1,2,3/1,3,5-trimethylbenzene = 0.37 at low, i.e., almost-equal-to 5% conversion]. The results of these catalytic tests rank NCL-1 as a large-pore zeolite possessing 12-membered ring channels with larger cavities. Probably, these cavities are present in the form of side pockets. The effective void space of zeolite NCL-1 seems to be comparable to that of mordenite.