A method for producing high surface area, thermally stable, microporous porous ceramic materials involves replacing a portion of the silicon in a sol or gel comprising silica (silicon dioxide) with cations of another metal. The metal-substituted silica sols are dried and fired to yield porous ceramic...http://www.google.es/patents/US5639412?utm_source=gb-gplus-sharePatente US5639412 - Substituted silica sol
