Formation of Catalytic Nanoparticles in Multilayer Polyelectrolyte Films
The above scheme illustrates one method for forming catalytic nanoparticles in multilayered polyelectrolyte films. Deposition of a film containing a polyamine-metal ion complex followed by reduction of the metal ion yields nanoparticles. The polyelectrolyte film prevents aggregation of nanoparticles, and TEM images suggest that typical particle sizes are about 3 nm. The polyelectrolyte film also allows selective catalysis. As shown schematically below, films of Pd nanoparticles deposited on alumina catalyze the hydrogenation of allyl alcohol at a rate that is twelve times faster than that for 3-methyl-1-penten-3-ol. More information on these systems can be found in Chemistry of Materials, 17, 301-307 (2005), Journal of the American Chemical Society, 126, 2658-2659 (2004) and Nano Letters, 2, 47-51 (2002). This work is supported by the American Chemical Society Petroleum Research Fund, and current studies focus on intramolecular selectivity in hydrogenation of double bonds. We are able to selectively hydrogenate terminal alkenes in the presence of other double bonds in the molecule.
