Facile preparation and electrochemical behavior of Pt100−xCox(111) single-crystal electrodes in 0.1 M HClO4

We describe the novel and facile preparation of Pt100− xCox alloy single-crystals and preliminary results on the electrochemical behavior of Pt100− xCox(111) surfaces in 0.1 M HClO4 solution as a function of Co composition. The prepared Pt-Co(111) surfaces were characterized by low energy electron diffraction and scanning tunneling microscopy; the results suggest the thermal formation of a Pt skin layer on the alloy surface. The cyclic voltammograms of the Pt100− xCox(111) electrodes exhibited increasingly negative shifts of the hydrogen adsorption onset potentials and positive shifts of the surface oxidation onset potentials as a function of the Co content due to the modified electronic structure of the Pt skin layer by the underlying Pt–Co alloy.