Highly efficient synthesis of high-silica SSZ-13 zeolite by interzeolite transformation of L zeolite at higher temperature

Abstract

High-silica SSZ-13 zeolites were synthesized rapidly and efficiently by interzeolite transformation of low-silica L zeolite at higher temperature in the presence of organic SDAs, additional SiO2 and SSZ-13 seeds. The obtained samples were characterized by XRD, SEM, N2-adsorption, FTIR, TG-DTG, 27Al MAS NMR and NH3-TPD measurements. The effects of temperature and SDA content on the crystallization process were investigated in detail. It was found that the crystallization time can be notably reduced at elevated temperature, and the SDA content in the starting gel can modulate flexibly the crystallization rate, solid yield, crystal size and acidity of samples. Additionally, the role of seed crystals during the interzeolite transformation process was also discussed. As a result, the pure SSZ-13 zeolites with high crystallinity were prepared in only 6h at 180 ​°C at SDA/SiO2 ratio of 0.2. Intriguingly, the solid yield of the samples under SDA/SiO2 ratio of 0.1–0.15 can reach ~96%. In addition, the samples exhibited good catalytic performance in methanol-to-olefins reaction.