Catalytic oligomerization of ethylene over Ni-containing MCM-22, MCM-41 and USY

Nickel ion exchanged MCM-22 and dealuminated Y zeolites with a controlled concentration of Ni 2+ and acidic sites were prepared, characterized, and tested in ethylene oligomerization performed in slurry batch mode (T=100–150°C, p=3.5 MPa). The catalytic behaviours of catalysts were discussed in connection with their pore size and acid properties and compared with those of the 36 pore size NiMCM-41 mesoporous materials. For the ethylene oligomerization the activity followed the order NiMCM-41 ≫ NiUSY > NiMCM-22. The main disadvantage of Ni-containing zeolites was the diffusion control of the oligomerization reactions that resulted in an enrichment of polymeric waxes in their pores.