Pressure-Assisted Fast Synthesis of Zeolitic Materials.

Abstract

Zeolites are widely utilized in various industrial applications, such as ion exchangers, catalysts, and adsorbents. However, traditional zeolite crystallization is time-intensive, requiring hours to weeks under autogenous pressure in autoclaves. In this study, we developed a novel and universal pressure-assisted method for the rapid synthesis of diverse zeolites, including MFI, CHA, FAU, MOR, *BEA, LTA, and AFI, as well as zeolite-encaged ultrasmall metal clusters and atoms, using batch reactors supercharged with controlled amounts of gases. Compared to traditional hydrothermal synthesis, this method significantly accelerates the crystallization rate of zeolites by 2-18 times. Experimental and theoretical analyses reveal that an elevated synthesis pressure and increased oxygen content in the system promote the formation of singlet oxygen species, thereby facilitating T-O-T (T═Si, Al, and P) bond restructuring and accelerating zeolite nucleation. This work offers a practical and efficient pathway for rapidly synthesizing zeolites to meet industrial demands while shedding light on the underlying mechanisms of zeolite crystallization.