Mixed cationic-anionic templating route to Al-MCM-48

A mixed cationic-anionic templating route to Al-MCM-48 is described with a low surfactant-to-silica molar ratio (0.25) and surfactant concentration (5 .0 wt%). Several features are characteristic of the product: high quality, an Si/Al ratio of 17, a larger unit cell, thicker and less strained pore wa lls, and improved hydrothermal stability. Furthermore, this route may be ex tended to the synthesis of Al-MCM-48 with Si/Al as low as 5.6 without detec table octahedrally coordinated aluminum. (C) 1999 Elsevier Science B.V. All rights reserved.