Structural Change and Electrochemical Behavior of Pt(100)-hex-R0.7° Surfaces in Gases and in Solution

Abstract

The structural change and electrochemical behavior of a Pt(100) surface in contact with gas, Ar gas, and solution were investigated by cyclic voltammetry in solution and low-energy electron diffraction and scanning tunneling microscopy in ultrahigh vacuum (UHV). The clean and well-defined Pt(100)-hex-R0.7° surface prepared in UHV was transformed into Pt(100)- upon being exposed to gas, whereas the Pt(100)-hex-R0.7° structure remained unchanged when exposed to Ar gas. Electrochemical measurements on both Pt(100)-hex-R0.7° and Pt(100)- electrodes were carried out in 1 mM It was demonstrated that the reconstructed Pt(100)-hex-R0.7° surface was stable in 1 mM in the potential range more anodic than that for hydrogen adsorption. The structural transition from hex-R0.7° to was observed at cathodic potentials where hydrogen atoms are adsorbed on the Pt electrode surface. © 2002 The Electrochemical Society. All rights reserved.