Preparation of Hierarchical Porous and Tunable Silicon Microenvironment SAPO-18 Sheets for Methanol-to-Olefins

In this study, hierarchically porous SAPO-18 catalystswith abundantintracrystalline mesopores were designed and fabricated with a cost-effectivenon-surfactant cationic surfactant (polydimethyldiallylammonium chloride,PDADMAC) as a pore-forming agent, morphology regulator, and siliconinducer by a one-step method. PDADMAC promoted the introduction ofsilicon atoms in the SAPO-18 framework, making the hierarchical porousSAPO-18 sheets present abundant optimized acidity. With the combinationof porous structure and suitable acid density, the hierarchical porousSAPO-18 sheets exhibited a threefold improvement in catalytic lifetimeand a 4% increase in ethylene and propylene selectivity during themethanol-to-olefin (MTO) reaction, compared with the conventionalSAPO-18 zeolite.

Automated summary

In this study, hierarchically porous SAPO-18 catalysts with abundant intracrystalline mesopores were successfully designed and fabricated. A cost-effective non-surfactant cationic surfactant, PDADMAC, was used as a pore-forming agent, morphology regulator, and silicon inducer. The resulting hierarchical porous SAPO-18 sheets showed improved catalytic performance compared to conventional SAPO-18 zeolite during the methanol-to-olefin reaction.