AVS 47th International Symposium
    Surface Science Monday Sessions
       Session SS1-MoA

Paper SS1-MoA6
Rapid Reactions on Nanofabricated Catalyst Pt Particles

Monday, October 2, 2000, 3:40 pm, Room 208

Session: Model Catalysts at High Pressures
Presenter: L. Österlund, Chalmers University of Technology, Sweden
Authors: L. Österlund, Chalmers University of Technology, Sweden
S. Johansson, Chalmers University of Technology, Sweden
B. Kasemo, Chalmers University of Technology, Sweden
Correspondent: Click to Email
The CO oxidation steady-state kinetics has been measured at atmospheric pressure on nanofabricated catalysts. The Pt/ceria and Pt/SiO@sub 2@ catalyst samples used in the present study were prepared by electron-beam lithography (EBL) technique as previously described.@footnote 1@ This technique offers unprecedented opportunities of preparing catalyst particles of well-defined size distribution. Simultaneously it opens the possibility of independently changing particle size, inter-particle distance and the interface between different components, respectively. Here we report results on fairly large, polycrystalline particles (700 nm diameter), as well as smaller crystalline particles formed by disintegration of Pt particles at well-controlled exposures to a H@sub 2@/O@sub 2@ gas mixture.@footnote 2@ The reaction kinetics of the CO oxidation, including the kinetic phase transition and the bistability region has been explored in detail theoretically.@footnote 3@ However, experimental results at high pressures are still by and large lacking. The results presented here fills this gap and provides new information of the kinetic parameters governing the reaction. Rapid reactions on nanometer particles can be very different from those on an infinite surface. Results of the reaction kinetics on the small Pt particles are discussed in this context . @FootnoteText@ @footnote 1@ S. Johansson et al. J. Vac. Sci. Technol. A 18, No 4 (2000). @footnote2@ K. Wong, S. Johansson, and B. Kasemo, Faraday Discuss. 105, 237 (1996). @footnote 3@ V. P. Zhdanov and B. Kasemo, Surf. Sci. Rep. 20, 111 (1994).