화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.150, No.2, E81-E88, 2003
Structural change and electrochemical behavior of Pt(100)-hex-R0.7 degrees surfaces in gases and in solution
The structural change and electrochemical behavior of a Pt(100) surface in contact with H-2 gas, Ar gas, and H2SO4 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-R0.7degrees surface prepared in UHV was transformed into Pt(100)-(1 x 1) upon being exposed to H-2 gas, whereas the Pt(100)-hex-R0.7degrees structure remained unchanged when exposed to Ar gas. Electrochemical measurements on both Pt(100)-hex-R0.7degrees and Pt(100)-(1 x 1) electrodes were carried out in 1 mM H2SO4. It was demonstrated that the reconstructed Pt(100)-hex-R0.7degrees surface was stable in 1 mM H2SO4 in the potential range more anodic than that for hydrogen adsorption. The structural transition from hex-R0.7degrees to (1 x 1) was observed at cathodic potentials where hydrogen atoms are adsorbed on the Pt electrode surface.