Ultrasmall ZeoliteL Crystals Prepared from Highly Interdispersed Alkali-Silicate Precursors

摘要

The preparation of nanosized zeolites is critical for applications where mass-transport limitations within microporous networks hinder their performance. Often the ability to generate ultrasmall zeolite crystals is dependent upon the use of expensive organics with limited commercial relevance. Herein, we report the generation of zeoliteL crystals with uniform sizes less than 30nm using a facile, organic-free method. Time-resolved analysis of precursor assembly and evolution during nonclassical crystallization highlights key differences among silicon sources. Our findings reveal that a homogenous dispersion of potassium ions throughout silicate precursors leads to the formation of a metastable nonporous phase, which undergoes an intercrystalline transformation to zeoliteL. The generation of highly interdispersed alkali-silicate precursors is seemingly critical to enhancing the rate of nucleation and facilitating the formation of ultrasmall crystal.