We have studied the effect of steam in the steam-assisted crystallization (SAC) of *BEA-type zeolite. It was found that after an aluminosilicate dry gel with SiO2/Al2O3 = 100 was treated with steam in an autoclave at 130 °C and autogenous pressure, the thermal treatment of a resulting product at 130 °C in an autoclave without the addition of water gave *BEA nanoparticles with a high crystallinity. It was presumed that pseudo-*BEA structures as intermediates were formed during the SAC treatment, and the dehydration of silanols in the pseudo-*BEA solids during the thermal treatment in the presence of a minimum amount of water possibly promoted the transformation of the pseudo-*BEA phase into *BEA crystalline phase with a periodicity in long-range order.
ASJC Scopus subject areas
- 化学 (全般)