| Abstract
| - In situ electrochemical scanning tunneling microscopy is used to study the coarsening of platinum islands atpotentials of 0.4, 0.5, and 0.6 V in the double-layer region. Several interesting surface island reconstruction processeswere observed, namely, (1) growth of small polycrystalline platinum islands; (2) shape- and size-limited platinumisland growth; and (3) growth of platinum islands accompanied by disappearance of nearby islands. It is evident thatthese potential-induced coarsening processes can be explained by Gibbs−Thomson theory as a variant of Ostwaldripening. Details of the island reconstruction processes are described, and the possible influences of these phenomenaon fuel cell operation are discussed.
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