Organic promoter-driven fast synthesis of zeolite beta and its acceleration mechanism

Abstract

Zeolite beta, an important catalytic material widely applied in the petrochemical field, is typically prepared under hydrothermal conditions. However, it usually suffers from the drawback of relatively long crystallization time. Herein, we show that the crystallization rate of zeolite beta can be accelerated by a factor of as much as about nine via the addition of the low-toxic and cost-effective pentacyclic lactam N-methyl-2-pyrrolidone (NMP) as a ‘promoter’. Using characterization techniques, we demonstrate that the pentacyclic lactam induces the fast formation of secondary building units (SBUs) and enhances the formation rate of the activated TEA⁺ species responsible for the nucleation of beta crystals. More importantly, the as-synthesized beta exhibited high product yield (above 85 wt%) and good performance in the direct amination of isobutene (i-C₄H₈) to tert-butylamine reaction.