Mesoporous Aluminosilicates from a Zeolite BEA Recipe

Abstract

We report the unusual formation of mesoporous aluminosilicates with enhanced properties from a zeolite recipe. The mesoporous aluminosilicates were prepared from a recipe typically used for the synthesis of microporous zeolite BEA. The key to the formation of a mesostructured material is use of a relatively low crystallization temperature and in particular a high Si/TEAOH ratio in the synthesis gel. The porosity of the aluminosilicates may be further modified by simple washing/refluxing (in water) steps performed on either the as-synthesized mesophase or the calcined material. This allows preparation of aluminosilicate materials that possess tunable mesoporosity with surface areas of 500−850 m2/g, pore volumes in the range of 0.35−1.5 cm3/g, and pore sizes between 25 and 140 Å. Depending on their synthesis temperature, the mesoporous aluminosilicates contain some zeolite building units within their framework and possess strong acid sites and high hydrothermal stability.