Electrochemistry of Fe(IV) and Mn(IV) corroles containing meso-dichlorophenyl substituents and the use of these compounds as catalysts for the electroreduction of dioxygen in acid media

Authors: LINA YE, ZHONGPING OU, DEYING MENG, MINGZHU YUAN, YUANYUAN FANG, KARL M. KADISH

Abstract: Two meso-dichlorophenyl substituted metallocorroles were synthesized and characterized as to their electrochemical and spectroelectrochemical properties in dichloromethane, benzonitrile, and pyridine containing 0.1 M tetra-n-butylammonium perchlorate (TBAP) as supporting electrolyte. The examined compounds are represented as (Cl_2Ph)_3CorFe^{IV}Cl and (Cl_2Ph)_3CorMn^{IV}Cl where (Cl_2Ph)_3Cor is the trianion of 5,10,15-tri(2,4-dichlorophenyl)corrole. Each metallocorrole was examined as to its catalytic activity for the electoreduction of dioxygen when coated on an edge-plane pyrolytic graphite electrode in 1.0 M HClO_4. Cyclic voltammetry combined with linear sweep voltammetry at a rotating disk electrode (RDE) and a rotating ring disk electrode (RRDE) was utilized to evaluate the catalytic activity for the electroreduction of O_2. The main O_2 reduction product is hydrogen peroxide under the given experimental conditions.

Keywords: Metallocorroles, synthesis, electrochemistry, catalytic activity, dioxygen reduction

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