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

Cyclic voltammetry and in situ FTIR spectroscopy were combined to study irr eversibly adsorbed cyanide adlayers in both perchloric and sulphuric media. Cyanide adlayers were formed on Pt(lll) 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 w hich tuning rates close to 100 cm(-1) V-1 below 0.5 V and 30 cm(-1) V-1 abo ve this potential were measured. These values are independent on the suppor ting electrolyte employed. A reorientation of the adsorbed cyanide was prop osed to explain the changes observed in both tuning rate and integrated int ensity at around 0.5 V. (C) 1998 Elsevier Science Ltd. All rights reserved.