Chemical Reactions Induced by Confined Electrons

The Cornell group studied the local dissociation of a chemisorbed, single O2 molecule on Pt(lll) in great detail. Obviously this system is of relevance in catalysis. It is known that oxygen adsorbs molecularly on Pt(lll) at temperatures below 100 K [85], When the temperature is increased to about 150 K, some of the O2 molecules desorb and the remaining molecules dissociate and recombine and de- 

Two iodobenzene molecules adsorbed at a Cu(lll) step edge, (b), (c) Iodine is abstracted together, from both molecules by applying a voltage 

The term nanocatalysis was introduced by Somorjai in 1994 when he used confined electrons of an STM tip to induce an electrochemical process. Earlier experiments on free clusters pointed towards the possibility of using small clusters with intrinsically confined valence electrons as catalysts to tune the properties atom-by-atom. These two completely different pioneering ideas have become further sophisticated during the last few years. It has become possible to use size-selected clusters on surfaces to catalyze simple chemical reactions and to tune the catalytic properties with size as well as using the tip of an STM to control every step of a chemical reaction on a local scale. With these examples a deeper understanding of nanocatalytic factors is now emerging and such studies will have profound impact on the catalysis of systems at the ultimate size limit. 

This work was supported by the Deutsche Forschungsgesellschaft (DEG). S.A. acknowledges the Swiss National Science Foundation and the Alexander von Humboldt Foundation for financial support. 

3 http //itri.loyola.edu/IWGN.Research. Directions/, eds. Roco, M. C., Williams, R. S., Alivisatos, P. 1999. 

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Chemical Reactions and Catalytic Processes on Free and Supported Clusters Chemical Reactions Induced by Confined Electrons Summary... 

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