Boosting the growth kinetics of extra-large-pore zeolite ZEO-1

Abstract

ZEO-1, the first stable aluminosilicate zeolite with extra-large pores, marks a great breakthrough in the zeolite community after decades of exploration and endeavors, opening possibilities for processing bulky substrates. However, the long synthesis cycle and relatively low reproducibility hinder the wide application of this intriguing material. This work developed a ‘deficient fluoride approach’ for ZEO-1 zeolite synthesis by adding a small amount of fluoride to induce a charge imbalance between the OSDA and fluoride. This approach significantly accelerates crystallization (15 times faster than the reported method) and achieves higher reproducibility than the originally reported protocol. Crystallization kinetics studies demonstrate the accelerating effect of stoichiometrically deficient fluoride anions on the nucleation and crystallization process. The ZEO-1 zeolites synthesized via the ‘deficient fluoride approach’ show catalytic activity for phenol alkylation with tert-butyl alcohol comparable to that of ZEO-1_LCS, but the products are evenly distributed, suggesting that more Brønsted acid sites might have been successfully introduced in the 16 MR channels. This work provides an incentive for feasible academic study and application of ZEO-1.