Embryonic zeolite-directed synthesis of zSM-34 and SSz-13 zeolites

The use of an organic structure-directing agent(OSDA)makes zeolite synthesis expensive and environmentally non-friendly.Seeded zeolite synthesis offers an environmentally benign alternative that avoids using an OSDA while providing a high purity,crystallinity,and yield in the product.In this study,we report using embryonic zeolites(EZs)as efficient seeds to obtain industrially important zeolites such as ZSM-34 and SSZ-13 in an OSDA-free synthesis system.Our results showed that zeolites zSM-34,SS-13 and LTL could be obtained depending on the Al/Si ratio in the synthesis system.The synthesis time was considerably shorter than other zSM-34 and SSZ 13 syntheses methods reported in the literature,achieving more than 90%crystallinity.The physicochemical analysis showed that highly crystalline zeolites with characteristics similar to the OSDA synthesized counterparts were obtained.Furthermore,the EZs seeding approach is facile,low cost,and environmentally friendly,pro-vided the synthesis is OSDA-free.In addition,the EZs seeds can be obtained under hydrothermal synthesis conditions.The method can be potentially applied to the synthesis of other zeolite types.