Synthesis and catalytic performance of a small crystal NaY zeolite with high SiO 2 /Al 2 O 3 ratio

O content of seeding. The catalytic performance of small crystal Y zeolite was evaluated in the hydrocracking of vacuum gas oil (VGO), the catalyst with smaller crystal Y zeolite presented higher VGO conversion and middle distillates selectivity than those with larger ones due to its higher surface area and more amount of mesoporous.