Electrocatalytic Reduction of Dioxygen by Cobalt Tetra(4-NN'N''-trimethylanilinium)porphyrin

DOI: 10.1039/f19848001139

Source and publish data:

Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases p. 1139 - 1150 (1984)

Update date:2022-08-29

Topics:

Authors:

Ozer, Dan

Parash, Rachel

Broitman, Federico

Mor, Uri

Bettelheim, Armand

Read Full Text PDF DownLoad Join now for total 90,000,000 free articles

Article abstract of DOI:10.1039/f19848001139

Cobalt tetra(4-NN'N''-trimethylanilinium)porphyrin (CoTMAP) has been studied in aqueous solutions using cyclic voltammetry, differential pulse voltammetry as well as by RRDE and spectroelectrochemical methods.The Co(III)/Co(II)TMAP couple dissolved in 0.05 mol dm^-3 H2SO4 has a redox potential of +0.14 V.The λ_max of the Soret band are 427 and 412 nm for Co(III) and Co(II)TMAP, respectively.The rate constant for the reaction between Co(II)TMAP and dioxygen in 0.05 mol dm^-3 H2SO4 was estimated to be 3E7 dm³ mol^-1 s^-1.The Co(III)TMP has been found to absorb at monolayer levels on glassy carbon surfaces and to have a catalytic effect on dioxygen electroreduction in aqueous solutions.This catalytic effect is strongly dependent on electrolyte pH.The overvoltage of O2 reduction is reduced by 480 mV and insignificant amounts of H2O2 are produced at pH 1, while an overvoltage decrease of 300 mV and an H2O2 yield of 70percent are observed at pH 8