Insight into the pore structure of zeolite MCM-22 through catalytic tests.

The pore structure of the new high-silica MCM-22 zeolite is discussed on the bases of product selectivities obtained in four model reactions, i.e., isomerization of m-xylene, toluene alkylation, hydroisomerization of n-decane, and n-heptane cracking. MCM-22 was seen to present characteristics of both 10MR and 12MR zeolites depending on the particular criterion used. This peculiar behavior was explained assuming the co-existence of both type of channels in the pore structure of MCM-22.