| Abstract
| - Pt nanoparticle array model catalysts with 28 ± 2 nm diameters and 100 ± 2 nm interparticle spacing havebeen fabricated with electron beam lithography on alumina supports. A novel method for cleaning the Ptnanoparticle arrays, involving low dosages of NO2 and CO and mild temperature flashing, was established.This cleaning procedure was crucial for measuring reaction rates over the nanoparticle arrays. The reactivityof the Pt/Al2O3 arrays was compared to a Pt(111) single crystal for the ethylene hydrogenation reaction. Theactivation energy and the pressure dependence of the H2 and C2H4 on the nanoparticle array were in excellentagreement with the kinetic data on the Pt(111) single-crystal model catalyst. Because the ethylene hydrogenationreaction is structure insensitive, the rate equation for Pt(111) can be applied to the Pt nanoparticle arrays. Thecalculated turnover frequency led to a calculated active metal surface area that compared very well with anactive metal surface area on the basis of geometry. This reaction can therefore be used to determine theactive metal surface area of the Pt nanoparticle array model catalysts. The arrays were characterized withAFM, SEM, XPS, and AES before and after being exposed to reaction conditions.
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