Correction to “Electrochemistry of Acids on Platinum. Application to the Reduction of Carbon Dioxide in the Presence of Pyridinium Ion in Water”

Correction to “Electrochemistry of Acids on Platinum. Application to the Reduction of Carbon Dioxide in the Presence of Pyridinium Ion in Water

Electrochemistry of Acids on Platinum. Application to the Reduction of Carbon Dioxide in the Presence of Pyridinium Ion in Water

A detailed cyclic voltammetric investigation of the reduction of moderately weak acids on platinum reveals that they are reduced in two steps: one involving the hydrated protons initially present at equilibrium and the second the reduction of the acid through its prior conversion into hydrated protons. The reduction of pyridinium ions (protonated pyridine) follows this reaction scheme as does any other acid of similar pK (e.g., acetic acid). Rather than being catalytically reduced, CO₂ plays a similar role through its prior conversion to carbonic acid. No trace of methanol or formate could be detected upon preparative-scale electrolysis of CO₂ on the same electrode in the presence of pyridinium ions

Proton-Coupled Intervalence Charge Transfer: Concerted Processes

The kinetics of proton-induced intervalence charge transfer (IVCT) may be measured electrochemically by generating one of the members of the IVCT couple in situ and following its conversion by means of the electrochemical signature of the other member of the couple. In the case of the diiron complex taken as an example, the reaction kinetics analysis, including the H/D isotope effect, clearly points to the prevalence of the concerted proton–intervalence charge transfer pathway over the stepwise pathways. A route is thus open toward systematic kinetic studies of proton-induced IVCT aiming at uncovering the main reactivity parameters and the factors that control the occurrence of concerted versus stepwise pathways