Hydrocracking of\nTetrahydronaphthalene for Preparation\nof Benzene and Alkylbenzene Catalyzed by Mo/Beta Sulfide Catalyst

Selective hydrocracking (HDC) of aromatic hydrocarbons\nis an important\nreaction to obtain high-value monocyclic aromatic hydrocarbons (MAHs)\nenriched with benzene, toluene, and xylene (BTX). The equilibrium\nrelationship between the metal and acid sites within the bifunctional\ncatalysts typically employed in this process remains unclear. Herein,\nwe report a Mo/beta catalyst with varying Si/Al ratio for HDC of tetrahydronaphthalene\n(THN) to evaluate the influence of acid site properties on the performance\nand stability of the HDC reaction. Mo/β-30 catalyst with a moderate\nSi/Al ratio exhibits optimal HDC performance and gives 36.5% of the\ndesired C6–C10 MAHs yield at a 63.7% conversion of THN for\n120 h. The promoted performance and stability of Mo/β-30 are\nattributed to the well-balanced state between abundant strong acid\nsites and the uniformly dispersed MoS<sub>2</sub> metal sites, which\nenables rapid transfer and further conversion of intermediate products\nbetween the two sites, thereby inhibiting the formation of byproducts\nand coke deposition. Notably, the Mo/β-30 catalyst is also found\nto be effective for the HDC of reformed heavy oil into BTX. It achieved\n77.0% BTX product selectivity at 44.0% conversion of polycyclic aromatic\nhydrocarbons (PAHs) over 245 h. This work will provide valuable insights\ninto the design and preparation of efficient industrial catalysts\nfor converting PAHs into high-value MAHs enriched with BTX.