Premium
Electrooxidation of Fe, Co, Ni and Cu Metalloporphyrins on Edge‐Plane Pyrolytic Graphite Electrodes and Their Electrocatalytic Ability towards the Reduction of Molecular Oxygen in Acidic Media
Author(s) -
Richards Gregory,
Swavey Shawn
Publication year - 2009
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.200900651
Subject(s) - chemistry , electrocatalyst , pyrolytic carbon , electrode , electrochemistry , porphyrin , redox , inorganic chemistry , highly oriented pyrolytic graphite , catalysis , bulk electrolysis , chemically modified electrode , graphite , cyclic voltammetry , photochemistry , working electrode , pyrolysis , organic chemistry
Edge‐plane pyrolytic graphite (EPG) electrodes coated with5,10,15,20‐tetrakis(4‐hydroxy‐3‐methoxyphenyl)porphyrin[H 2 T3M4HPP] and its Fe III , Co II , Ni II and Cu II analogs undergo an electrochemical/chemical/electrochemical (ECE) reaction when anodically scanned in 0.5 M H 2 SO 4 . The new redox couple formed from this anodic conditioning of the coated electrode is dependent on the pH of the solution. Roughened EPG electrodes coated with the metalloporphyrins show a catalytic shift for the reduction of O 2 when compared to the reduction of O 2 at a bare EPG electrode. An additional catalytic shift of approximately 100 mV is observed for O 2 reduction at an EPG electrode coated with the Co II porphyrin, which has been oxidized in 0.5 M H 2 SO 4 . In addition to the added electrocatalysis, approximately 15 % of the O 2 reduced at the oxidized Co II porphyrin EPG electrode is converted to H 2 O as determined by rotating‐disk electrode measurements.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)