Two-Dimensional FT-IR Correlation Analysis of the Chemisorption of Nitric Oxide on Pt(100)

In addition to the previously reported vibrational frequencies of NO stretch at 1591–1650 cm⁻¹ and 1770–1800 cm⁻¹ on Pt(100) surface at 300 K, we observed an infrared spectral band centered around 1689–1692 cm⁻¹. With the use of two-dimensional IR correlation analysis, we were able to distinguish the various adsorption sites of NO under the present experimental conditions. The infrared band at 1689–1692 cm⁻¹ developed independently of the band at 1639–1654 cm⁻¹. By varying the pressure of NO and the surface temperature, we were able to demonstrate that the 1689–1692 cm⁻¹ band grows only at higher NO pressure and lower surface temperature.