Platinum Metals Rev., 2001, 45, (4), 174
Tailored Palladium/Silica Spheres
The ability to control the preparation of porous materials used as supports is important in the fields of heterogeneous catalysis and molecular sieving. Templates of colloidal silica crystals and anion exchange resins have resulted in controlled pore sizes and macrosteuctures.
Now, researchers from Sweden report the synthesis of Pd-containing silica spheres prepared by using anion exchange resins as templates (L. Tosheva and J. Stette, Chem. Commun ., 2001, (12), 1112-1113).
Their method is based on the fact that the resinsilica composite, obtained after the ion exchange of silica species, retains a high anion exchange capacity. This allows the introduction of negatively charged ions, such as PdCl42-. Calcination removes the resin bead template and the Pd is converted to an oxide form. Hard, solid silica spheres with a controllable amount of Pd can be prepared by this technique. With their high surface areas and large pore volumes, these materials may be useful for catalytic applications.