Non-aqueous cross hydrolysis: an epoxide-free sol-gel route toward highly porous alumina monoliths

Abstract

Highly porous alumina monoliths can be fabricated by simultaneous hydrolysis of aluminum alkoxides and salts as homonuclear precursors. The use of carcinogenic epoxides can thus be avoided. In this novel approach, no water is added to the system but hydrolysis is induced by the crystal water of the aluminum salt. Mechanical stabilization and significantly increased porosity values can be achieved when the sol-gel synthesis is performed in an autoclave.