Zeolites are among the most frequently used industrial catalysts and are of fundamental importance in the production of the great majority of our fuels and chemicals. Their active sites, generated at or near the isomorphously substituted aluminum centers, reside mostly inside the microporous system. This spatial constraint imparts selectivity (substrate, product, and transition state), but at the cost of increased diffusion barriers. In the limiting case, very bulky substrates can interact only with those catalytic centers located on the external surface of the zeolite crystallite, dramatically reducing the utility of zeolites in such circumstances.
Thomas Maschmeyer, The University of Sydney, Australia, and colleagues report a new one-pot method to prepare a highly active and yet selective and stable acidic micro-/mesoporous zeolite catalyst composite. The process involves generating highly dispersed zeolitic sheets (ITQ-2) inside the synthesis gel of a mesoporous host structure (siliceous TUD-1) by in situ delamination of MCM-22 zeolite.
- An ITQ-2/TUD-1 Micro-/Mesoporous Composite: In Situ Delamination as a Tool for the Preparation of Innovative Materials,
Cindy C. Aquino, Heloise O. Pastore, Anthony F. Masters, Thomas Maschmeyer,
ChemCatChem 2011, 3, 1759–1762.