Title
Dendrimer Templates for Heterogeneous Catalysts: Bimetallic Pt-Au Nanoparticles on Oxide Supports
Document Type
Article
Publication Date
6-24-2008
Abstract
Polyamidoamine (PAMAM) dendrimers were used to template Pt, Au, and bimetallic Pt–Au dendrimer encapsulated nanoparticles (DENs) in solution. Adjusting the solution pH allowed for slow, spontaneous adsorption of the nanoparticles onto silica, alumina, and titania. After dendrimer removal, the catalysts were characterized with infrared spectroscopy of adsorbed CO and tested with CO oxidation catalysis. Infrared spectroscopy of the monometallic Pt catalysts showed a slight shift in the CO stretching frequency for the different supports. For the bimetallic catalysts, infrared spectra showed CO adsorbed on both Pt and on Au sites. Spectra collected during CO desorption showed substantial interactions between the two bands, confirming the presence of bimetallic particles on all the supports. The bimetallic catalysts were found to be more active than the monometallic catalysts and had lower apparent activation energies. The titania supported Pt–Au catalyst was resistant to deactivation during an extended treatment at 300 °C. Correlations between IR spectra and catalytic activity showed differences between the mono- and bimetallic materials and implicated a bimetallic Pt–Au ensemble at the catalytic active site. This is the first study to show that DENs are appropriate precursors for studying support effects on catalysis by metal nanoparticles, although the magnitude of the effects were small.
DOI
10.1016/j.apcatb.2007.12.012
Publisher
Elsevier
Repository Citation
Auten, B. J., Lang, H., & Chandler, B. D. (2008). Dendrimer templates for heterogeneous catalysts: Bimetallic Pt–Au nanoparticles on oxide supports. Applied Catalysis B: Environmental, 81(3-4), 225-235. https://doi.org/10.1016/j.apcatb.2007.12.012
Publication Information
Applied Catalysis B: Environmental