1-hexene aromatization is a promising technology to convert excess olefin in fluid catalytic cracking (FCC) gasoline to high-value benzene (B)

toluene (T)

and xylene. Besides

the increasing market demand of xylene has put forward higher requirements for new generation of catalyst. For increasing xylene yield in 1-hexene aromatization

the effect of mesopore structure and spatial distribution on product distribution and Zn loading was studied. Catalysts with different mesopore spatial distribution were prepared by post-treatment of parent HZSM-5 zeolite

including NaOH treatment

tetra-propylammonium hydroxide (TPAOH) treatment

and recrystallization. It was found the evenly distributed mesopore mainly prolongs the catalyst lifetime by enhancing diffusion properties but reduces the aromatics selectivity

as a result of damage of micropores close to the catalyst surface. While the selectivity of high-value xylene can be highly promoted when the mesopore is mainly distributed interior the catalyst. Besides

the state of loaded Zn was also affected by mesopores spatial distribution. On the optimized catalyst

the xylene selectivity was enhanced by 12.4% compared with conventional Zn-loaded parent HZSM-5 catalyst at conversion over 99%. It was attributed to the synergy effect of mesopores spatial distribution and optimized acid properties. This work reveals the role of mesopores in different spatial positions of 1- hexene aromatization catalysts in the reaction process and the influence on metal distribution

as well as their synergistic effect two on the improvement of xylene selectivity

which can improve our understanding of catalyst pore structure and be helpful for the rational design of high-efficient catalyst.