Structure and Activity of Ni₂P/Desilicated Zeolite β Catalysts for Hydrocracking of Pyrolysis Fuel Oil into Benzene, Toluene, and Xylene

The effects of desilication (DS) of the zeolite β on the hydrocracking of polycyclic aromatics were investigated using the Ni₂P/β catalysts. The Ni₂P/β catalysts were obtained by the temperature-programmed reduction (TPR) method, and the physical and chemical properties were examined by N₂ physisorption, X-ray diffraction (XRD), ²⁷Al magic angle spinning–nuclear magnetic resonance (²⁷Al MAS NMR), extended X-ray absorption fine structure (EXAFS), isopropyl amine (IPA) and NH₃ temperature-programmed desorption (TPD), CO uptake, and thermogravimetric analysis (TGA). The catalytic activity was examined at 653 K and 6.0 MPa in a continuous fixed bed reactor for the hydrocracking (HCK) of model compounds of 1-methylnaphthalene (1-MN) and phenanthrene or a real feedstock of pyrolysis fuel oil (PFO). Overall, the Ni₂P/DS-β was observed as more active and stable in the hydrocracking of polycyclic aromatics than the Ni₂P/β catalyst. In addition, the Ni₂P/β suffered from the coke formation, while the Ni₂P/DS-β maintained the catalytic stability, particularly in the presence of large polycyclic hydrocarbons in the feed.