Hierarchical Molecular Highway Architectures in SAPO-34 Single Crystals Boost Methanol-to-Olefins Catalytic Performance

The persistent challenge of catalyst deactivation in methanol-to-olefins (MTO) conversion, primarily arising from restricted molecular transport and subsequent coke accumulation in conventional microporous SAPO-34 zeolites, necessitates innovative structural solutions. Herein, we demonstrate a synthesis strategy that employs sucrose-derived carbon as a hard template combined with vapor-phase transport to fabricate hierarchical SAPO-34 single crystals, thereby overcoming the low crystallinity and poor pore connectivity that have previously plagued hierarchical SAPO-34 zeolites. This intracrystalline hierarchical architecture with highly interconnected pores demonstrates molecular highway functionality and exhibits a 77.5% increase in propylene diffusion coefficient compared to conventional samples. Such hierarchical molecular highway architecture effectively regulates coke distribution within SAPO-34 crystals during MTO reactions. The optimized hierarchical SAPO-34 exhibits a 505 min operational lifetime, a 3.3-fold enhancement in catalytic durability over traditional microporous systems. Our findings establish a materials design paradigm for overcoming diffusion-reaction trade-offs in zeolite catalysis, with implications extending beyond conventional MTO processes.