Organotemplate-free and seed-directed synthesis of levyne zeolite

Small-pore zeolite levyne has been successfully synthesized following an organotemplate-free route using RUB-50 zeolite as seeds with the aid of a small amount of alcohols. Physicochemical characterization with a combination of techniques including XRD, N2 adsorption, FE-SEM, 27Al and 29Si NMR, and TPD-NH3 shows that the zeolitic product from this seed-directed organotemplate-free synthesis approach (designated as LEV-SDS) has good crystallinity, high surface area, uniform crystals, tetrahedral Al3+ species, and abundant acidic sites. It is also found that alcohols play an important role in preparation of LEV-SDS zeolite by inhibiting the formation of MOR zeolite. Catalytic tests for the conversion of methanol-to-olefins (MTO) show that H-form of LEV-SDS zeolite exhibits good conversion of methanol and high selectivities for ethylene and propylene, which could be potentially important for using LEV-SDS zeolite as a catalyst in MTO reaction.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Levyne zeolite has been synthesized by a seed-directed organotemplate-free route. ► Alcohols are co-solvents for preparation of LEV-SDS zeolite. ► The LEV-SDS zeolite has good crystallinity and tetrahedral Al3+ species. ► The LEV-SDS zeolite exhibits good performance for MTO reaction.