IZM-2: A promising new zeolite for the selective hydroisomerization of long-chain n-alkanes

IZM-2 (IFPEn Zeolitic Material number 2) is an aluminosilicate zeolite with unknown structure. The synthesis is performed using 1,6-bis(methylpiperidinium)hexyl dibromide template. According to SEM and TEM, IZM-2 particles consist of intergrowths of 20–60 nm nanocrystals of various orientations. The nitrogen adsorption isotherm is characteristic of a nanosize microporous material. Characterization of the pore architecture using m-xylene isomerization and disproportionation and n-decane isomerization-hydrocracking test reaction suggests the presence of two types of pores of different diameter. The catalytic fingerprints of 10-membered ring pores are observed and concluded to be present next to wider pores, tentatively qualified as 12-membered ring pores. Pt/IZM-2 was evaluated in the hydroisomerization of n-hexadecane. Pt/IZM-2 is an excellent hydroisomerization catalyst especially suited for formation of multi-branched skeletal isomers. IZM-2 is a valuable addition to the family of 10-membered ring zeolites and may find application in hydroisomerization processes for selective hydroisomerization of long-chain n-alkanes.