Hydrogen adsorption on Pt(100), Pt(110), Pt(111) and Pt(1111) electrode surfaces studied by in situ infrared reflection absorption spectroscopy

Hydrogen adsorption on Pt(100), Pt(1111) (6(100) × (111)), Pt(110) and Pt(111) electrode surfaces was studied by both voltammetry and in situ infrared reflection absorption spectroscopy. The terminal hydrogens absorbed on Pt(100), Pt(1111) and Pt(110) electrodes were observed at 1990–2080 cm−1 as bands appearing at potentials more negative than 0.25, 0.1 and 0 V versus SHE, respectively. However, a well-oriented pt(111) electrode did not give a significant absorption of the terminal hydrogens under similar conditions. The terminal hydrogen adsorption was sensitive to the surface crystallographic orientation.