On the mechanism of dioxygen electroreduction at transition metal meso-tetrakis pyridyl porphyrins—a comparative spectroelectrochemical study

✍ Scribed by S. Popovici; W. Leyffer; R. Holze

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 193 KB
• Volume: 03
• Category: Article
• ISSN: 1088-4246
• DOI: 10.1002/(sici)1099-1409(199904)3:4<265::aid-jpp131>3.0.co;2-e

✦ Synopsis

The mode of interaction with and the mechanism of the dioxygen reduction reaction at six transition metal α,β,γ,δ-tetra(4-pyridyl)porphyrins (MeTPyPs) deposited on carbon and silver supporting electrodes were investigated with cyclic voltammetry, FTIR and UV-vis spectroscopy and resonance Raman spectroscopy. Results indicate a strong influence of both the ligand and the central metal ion upon the reduction electrocatalysis in terms of electrode overpotentials. Spectroelectrochemical results support a two-electron pathway resulting in hydrogen peroxide as the primary reduction product. A significant influence of the central ion on the vibrational behaviour and the dioxygen reduction mechanism was not found.