Seeding-induced nano-sized SAPO-34 synthesis with superior MTO performance: Energy-efficient approach with highly reduced OSDA consumption

Abstract

Abstract Methanol-to-olefin conversion is one of the most successful approaches to producing light olefins. It has been proved that SAPO-34 is the best catalyst for this process. This molecular-sieve is characterized by high thermal stability, moderate acid sites, and shape selectivity. In this report, SAPO-34 was synthesized using the seed-assisted method. Effects of OSDA and seed on crystallinity and particle size were investigated using Central Composite Design. Samples were characterized by XRD, FE-SEM, FTIR, BET, EDX, and TPD. Results showed that the samples had excellent physicochemical properties. The design of Experiments could predict the results accurately (R2 > 0.9). It was demonstrated that template was the key factor in the seed-assisted synthesis of SAPO-34. Template consumption was reduced by 50%, and it was proved that the synthesis time could be effectively decreased to 3 h due to rapid nucleation. Samples exhibited 100% methanol conversion and up to 90% selectivity toward ethylene and propylene.