Prepared by Electrochemical Ru Deposition

CO oxidation was studied on Ru decorated Au(lll) electrodes in order to clarify the effect caused by the substrate and the electronic modification by nanosized Ru islands.12 l4,16 Since the Au( 111) surface is inactive for CO adsorption or oxidation at potentials lower than l.Oy15 55 56 the reaction on Ru/Au(lll) was limited to the Ru nanoislands themselves. CO stripping voltammetry curves of Ru/Au(l 11) surfaces prepared by electrochemical Ru deposition, obtained after 5-min CO adsorption at -0.25 V and subsequent purging of the solution with argon,12,16 are presented in Fig. 19. 

To explain the quite complex CO stripping behavior, various aspects have to be taken into consideration, including the adsorption 

The CO stripping voltammetry for Ru/Au(l 11) prepared by 3-min spontaneous deposition from 1 mM RuC/3 in 0.1 M HCIO4 is depicted in Fig. 20. The CO stripping is shown as a solid line, whereas the second sweep, which is shown as a dotted line, indicates the complete removal of CO from the solution and represents CV of the Ru/Au(l 11) surface in 0.5 M H2SO4 (see also Fig. la). 

The observed CO stripping currents from Ru/Au(l 11) surfaces are attributed to partially oxidized Ru islands,9 as in the above-described case of Ru/Au(l 11) surfaces obtained by electrochemical deposition. Two main peaks associated with CO stripping were 

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