Insertion of extra-framework Al into the framework of mesoporous MCM-41 aluminosilicates

Abstract

Virtually all octahedrally coordinated (extra-framework) Al in calcined Al-grafted MCM-41 materials can be inserted into (tetrahedral) framework positions upon treatment with an aqueous solution of NH₄OH; the insertion of Al into the framework is accompanied by an increase in (Brønsted) acidity and ion exchange capacity.