Controllable synthesis of nanoscaled ZSM-5 aggregates with multivariate channel under the synergistic effect of silicate-1 and TPABr using dual-silica source

ZSM-5 zeolite offering a short diffusion length via constructing multivariate channel structure are highly demanded for a series of catalytic process. In this work, a facile strategy toward synthesizing nanoscaled ZSM-5 aggregates having a multivariate channel structure was developed using silica sol and water glass as dual-silica source, silicate-1 as nucleus inducing the crystal aggregation, and TPABr as structure-directing agent (SDA). Introduction of a certain amount of water glass not only could avoid the usage of alkalinity source, but also moderately adjust the polymerization and depolymerization rate of silicon species. In addition, a synergistic effect were found between silicate-1 and TPABr. Part of TPA+ would adsorb on the surface of seed to compensate the surface negative charge. Consequently, crystal growth could rapidly occurs on the surface of seed. Herein, the crystal size and particles size can be flexibly adjusted by controlling the TPABr and seed content, respectively. Such approach in synthesis of nanoscales ZSM-5 aggregates is versatile and applicable for the industrial production.