Potential and time dependent broad band sum frequency generation spectroscopic study on electrochemical oxidation of adsorbed CO on Pt(1 1 1) electrode surface in pre-peak region in alkaline solution

In situ broad band sum frequency generation (SFG) spectroscopy was applied to clarify the oxidation mechanism of adsorbed CO on Pt(1 1 1) electrode in alkaline solution comparison with that acidic solution. A single SFG peak due on-top site observed region 1950 – 2150 cm−1. While proceeded a nucleation-growth mode via Langmuir–Hinshelwood (L-H) by reacting OH main 0.1 M HClO4 solution, oxidized random model Eley-Rideal (E-R) OH− pre-peak NaOH The anodic still even after totally disappeared region, showing there existed inactive CO, although its structure not clear.