Synthesis of Zeolite ZSM3 from Faujasite: Effects of Post-synthesis Ageing and Insitu seeding

Abstract

The crystallization of ZSM3 via faujasite metamorphosis, synthesized from dealuminated metakaolin, was achieved without the addition of any structure directing agent. The XRD, XRF, and SEM/EDXS analyses carried out on the sample indicated successful synthesis of matrix, containing zeolites X, Y and sodium aluminosilicate, in various proportions, which was later transformed completely into ZSM3. The XRD peaks and SEM morphologies attributed to ZSM3 increased in intensity and crystallinity, as reaction and ageing time progressed. Post synthesis effects i.e. exposure to dampness and longer contact time in the presence of residue/unwashed NaOH used for the synthesis earlier, were totally responsible for the metamorphosis. Anatase and quartz were observed to persist in the raw, intermediate and as-synthesized product, pointing to their high level of resistances to treatments. The formation of competitive zeolite phases, was prevented by controlling factors responsible for its nucleation and formation.

Keywords: metamorphosis, insitu seeding, kaolin, ZSM3, faujasite, dealumination, aging