From nanoparticles to hierarchical structures: Controlling the morphology of zeolite beta

Abstract

Zeolite beta (Si/Al∼18) was synthesized from a single template reaction mixture in a one-step hydrothermal treatment. By adjusting the synthesis conditions, the formation of isolated nanocrystals or mesoporous aggregates of zeolite beta was achieved. Depending on the synthesis conditions, zeolite beta nanocrystals of approximately 20–150 nm in diameter or mesoporous aggregates of approximately 120–140 nm in diameter were prepared. The use of concentrated synthesis gels resulted in mesoporous aggregates of nanocrystals and diluted reaction mixtures resulted in isolated zeolite nanoparticles. The crystallinity of the samples determined from pXRD patterns is similar to that of commercially available micron-sized zeolite beta. The samples had surface areas of greater than 600 m 2/g and mesopore volumes of 0.4–0.5 cc/g.