Role of Zeolite Acidity and Ni Content in Hexadecane Hydroisomerization over Ni/ZSM-23 Catalyst

In this work, a series of ZSM-23 zeolite samples having different acidity due to various Si/Al ratios (30, 50, and 100) was synthesized using DMFA as a template. Two series of bifunctional Ni/ZSM-23 catalysts were prepared: the first one with different Ni content and the second one with different zeolite acidity. Samples were characterized by a set of physicochemical methods and tested in a hexadecane isomerization reaction. It was shown that an increase in the nickel content from 2 to 5 wt % significantly enhanced hexadecane conversion and iso-C16 yield. The catalyst activity depends almost linearly on the zeolite acidity. The maximum iso-C16 yield of 76 wt % was achieved over Ni/ZSM-23 catalyst with a Si/Al ratio of 50 having moderate acidity. The results demonstrate the prospects for implementing low-cost nickel-containing zeolite catalysts for an industrially important reaction such as the hydroisomerization of middle distillates and heavier petroleum fractions.