Spectroelectrochemical study on CN− adsorbed at Pt(111) in sulphuric and perchloric media

Abstract

Cyclic voltammetry and in situ FTIR spectroscopy were combined to study irreversibly adsorbed cyanide adlayers in both perchloric and sulphuric media. Cyanide adlayers were formed on Pt(111) single-crystal electrodes and are stable in a wide range of potentials. A vibrational band at around 2100 cm−1 was assigned to the C–N stretching vibration of adsorbed cyanide, for which tuning rates close to 100 cm−1 V−1 below 0.5 V and 30 cm−1 V−1 above this potential were measured. These values are independent on the supporting electrolyte employed. A reorientation of the adsorbed cyanide was proposed to explain the changes observed in both tuning rate and integrated intensity at around 0.5 V.