文摘
This work presents characteristics of Pt deposits on Au(111) obtained by the use of spontaneous deposition andinvestigated by electrochemical scanning tunneling microscopy (EC-STM). On such prepared and STM characterizedAu(111)/Pt surfaces, we studied electrocatalytic oxidation of formic acid and methanol. We show that the first monatomiclayer of Pt displays a (3 × 3)R30 surface structure, while the second layer is (1 × 1). After prolonged deposition,multilayer Pt deposits are formed selectively on Au(111) surface steps and are 1-20 nm wide and one to five layersthick. On the optimized Au(111)/Pt surface, formic acid oxidation rates are enhanced by a factor of 20 compared tothose of pure Pt(111). The (3 × 3)R30-Pt yields very low methanol oxidation rates, but the rates increasesignificantly with further Pt growth.