Synthesis and consequence of three-dimensionally ordered macroporous Beta zeolite supported NiW catalyst for efficient hydrocracking of 1-methylnaphthalene to BTX

We fabricated the three-dimensionally ordered macroporous Beta (3DOM-Beta) zeolite supported NiW sulfide catalyst for efficient hydrocracking of 1-methylnaphthalene (1-MN) to BTX, in which a high hydrocracking activity ( TOF =2.11×10 -2 ∙s −1 ) and 40.7% BTX selectivity were realized. • 3DOM-Beta zeolite with three-dimensional ordered macroporous structure was composed. • 3DOM-Beta zeolite effectively facilitates the accessibility of active sites and diffusion. • NiW/3DOM-Beta showed a high activity and BTX selectivity for 1-MN hydrocracking. The three-dimensionally ordered macroporous Beta (3DOM-Beta) zeolite was prepared and used as support of NiW sulfide catalyst for hydrocracking. The as-prepared NiW/3DOM-Beta catalyst possessed a high specific surface area and external specific surface area up to 499 m 2 /g and 241 m 2 /g, respectively, and a small average layer length (3.62 nm), a high highest average stacking number (4.64) and dispersion ( f W =0.24) of metal sulfide phase, which are characteristic of high hydrogenation activity. Its high mesopore volume (0.25 cm 3 /g) and the highly ordered interconnected macro-meso-microporosity hierarchical structure significantly facilitated diffusive mass transfer. Compared to the NiW sulfide supported on conventional Beta (C-Beta), alkali-treated Beta (A-Beta) and nanosized Beta (Nano-Beta) zeolites, NiW/3DOM-Beta catalyst showed the highest BTX selectivity and yield of 40.7 % and 40.2 % (33.2 % and 32.6 % on NiW/C-Beta, 34.8 % and 33.9 % on NiW/A-Beta, 37.2 % and 36.6 % on NiW/Nano-Beta), and the highest hydrocracking activity ( TOF =2.11 × 10 -2 ∙s −1 ) as well as the smallest coking content (6.7 wt%). This work not only reveals the promotion effects of the ordered mesopore structure of supports on metal dispersion, accessibility of acid sites, diffusion of reactants and products for designing hydrocracking catalyst, but also shows the potential practical application of 3DOM zeolites with interconnected macro-meso-microporosity for the efficient catalytic conversion of macro-hydrocarbons via hydroupgrading.