Optimizing Metal Sites in Hierarchical USY for Selective Hydrocracking of Naphthalene to BTX.

Metal components (CoMo, NiMo, NiW) supported on hierarchical porous USY zeolite (HPY) were systematically optimized for selective naphthalene hydrocracking to BTX (benzene, toluene, xylene). The hierarchical porosity enhanced mass transport and accessibility to active metal sites, improving reaction selectivity and efficiency. Supported metal sulfides served as hydrogenation sites, crucial for aromatic ring activation and coke suppression. By optimizing the synergy between hydrogenation and cracking functions, the optimized Ni1W/HPY catalyst achieved complete naphthalene conversion with a BTX yield of 92.5%. The spatial distribution of WO3 crystallites facilitated functional separation, promoting selective conversion. These findings underscore the importance of metal-acid balance and pore architecture in designing efficient hydrocracking catalysts.