Realizing Fast Synthesis of High-Silica Zeolite Y with Remarkable Catalytic Performance

High-silica zeolite Y (FAU) plays a vital role in (petro)chemical industries. However, the slow nucleation and growth kinetics of the high-silica FAU framework limit its direct synthesis and the improvement of framework SiO2/Al2O3 ratio (SAR). Here, a facile strategy is developed to realize the fast crystallization of high-silica zeolite Y, which involves the combination of high crystallization temperature, ultra-stable Y (USY) seeds and efficient organic-structure directing agent (OSDA). The synthesis can be finished in 5-16 h at 160 degrees C and with tunable SAR up to 18.2, and the key factors affecting crystallization kinetics and phase purity are elucidated. Moreover, the crystallization process was monitored to reveal the fast crystal growth mechanism. The high-silica products possess high (hydro)thermal stability and abundant strong acid sites, which endow them excellent catalytic cracking performance, obviously superior to commercial USY.

Automated summary

High-silica zeolite Y plays a crucial role in (petro)chemical industries, but its slow nucleation and growth kinetics hinder direct synthesis and improvement of framework SiO2/Al2O3 ratio. In this study, a facile strategy involving high crystallization temperature, ultra-stable Y seeds, and efficient organic-structure directing agent is developed to achieve fast crystallization of high-silica zeolite Y. The synthesis can be completed in 5-16 hours at 160 degrees C, with adjustable framework SiO2/Al2O3 ratio up to 18.2, and the key factors affecting crystallization kinetics and phase purity are explained. Additionally, the fast crystal growth mechanism is revealed through monitoring the crystallization process. The high-silica products exhibit high (hydro)thermal stability and abundant strong acid sites, resulting in excellent catalytic cracking performance superior to commercial ultra-stable Y.