An environmentally friendly route to prepare hierarchical ZSM-12 using waste liquor as partial nutrients

Abstract

Abstract Waste liquor generated in the synthesis of zeolite usually contains water as well as alkali and residual silicon-aluminum species. It will not only bring an environmental pollution but also cause wasting of resources if being directly emitted. A friendly and low-cost synthesis route was developed for preparing hierarchical ZSM-12 by using waste liquor of mordenite zeolite as partial nutrients. Where, primary or/and secondary-structure units in the waste liquor triggered an explosive nucleation rate. Nano-sized zeolite crystals were therefore created during the initial stage, and subsequently loosely aggregated into hierarchically bulky materials by self-assembly. The as-synthesized samples were characterized by XRD, FT-IR, SEM, TEM and N2 adsorption/desorption techniques. The as-synthesized materials were also investigated on an IGA apparatus using n-octane as a probe molecule so as to reveal the effect of the size of the primary crystals in the aggregates on the diffusion properties of the loosely aggregating hierarchical ZSM-12.