Rapid and facile synthesis of hierarchical nanocrystalline SSZ-13 via the interzeolite transformation of ZSM-5†
Hierarchical SSZ-13 was successfully synthesized via the interzeolite conversion of ZSM-5 with high framework density (FD = 18.4 T/1000 Å3) in the presence of N,N,N-trimethyl-1-adamantanamine hydroxide (TMAdaOH) under hydrothermal conditions. Compared with conventional SSZ-13, SSZ-13 derived from the interzeolite conversion of ZSM-5 possessed many merits, such as a shorter crystallization time (only 4 h), high crystallinity, high yield (73–77%), hierarchical pores, and smaller crystal size (800 nm). XRD, SEM and N2 adsorption–desorption were used to trace the crystallization process, which allowed us to propose the synthesis mechanism of converting ZSM-5 to SSZ-13. Meanwhile, the interzeolite conversion mechanism was presumed to be that the secondary structural unit of ZSM-5 was decomposed through alkali solution treatment, and the multi-membered rings were destroyed, further reassembling into SSZ-13 under the guidance of the template. This is an alternative strategy for synthesizing a hierarchical SSZ-13 zeolite.