II International Symposium on Carbon for Catalysis ABSTRACTS

OP-<strong>II</strong>-8
effect, electrochemistry provides a means by which virtually any metal can be deposited at a
precisely known coverage onto a conductive surface from ionic solution.
We investigated the electrocatalytic activity of nano and mesoscale silver particles
deposited onto Glassy Carbon (GC) towards the electrochemical reduction of a model organic
halide, namely benzyl chloride.
The working electrodes were built from a 6 mm diameter GC rod (Tokai GC-20) and
were polished to a mirror finish with emery paper of decreasing grain size followed by
diamond paste (3, 1 and 0.25 μm particle size). They were then cleaned in ethanol in an
ultrasonic bath for about 5 minutes.
The electrodeposition of Ag was achieved by carrying out a chronoamperometry in a
solution of 1 mM AgClO 4 in CH 3 CN + 0.1 M LiClO 4 for different time intervals (typically
20-80 s) at a diffusion limit potential (– 0.4 V vs Ag + /Ag). In this way we obtained a regular
deposit of Ag nanoparticles 100-200 nm in size.
Reduction of PhCH 2 Cl on such a modified surface takes place practically at the same
potential as at bulk Ag, which is ca. 500 mV less negative than the reduction potential at GC.
Preparative-scale electrolyses of 10 mM solution of PhCH 2 Cl in CH 3 CN + 0.1 M TEAP
carried out at a modified GC plates, gave a two electrons reduction process in good agreement
with results obtained at bulk Ag [4].
References
1 D.G. Peters, In Organic Electrochemistry, 4 th ed., H. Lund and O. Hammerich, Eds.,
Marcel Dekker, New York, 2001, p. 341.
2 C.P. Andrieux, A. Le Gorande, J.-M. Savéant, J. Am. Chem. Soc. 114 (1992) 6892.
3 S. Ardizzone, G. Cappelletti, L.M. Doubova, P.R. Mussini, S.M. Passeri, S. Rondinini,
Electrochim. Acta 48 (2003) 3789.
4 A.A. Isse, A. Gennaro, Chem. Commun. (2002) 2798.
5 H. Liu, R.M. Penner, J. Phys. Chem. B, 104 (2000) 9131.
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