Abstract

ARCE, ROXANA et al. SULFITE OXIDATION MEDIATED BY ORTHO-PHENYLENEDIAMINE / CO(II)-TETRAKIS(PARA-AMINOPHENYL)PORPHYRIN COPOLYMERS IN ACID MEDIUM. J. Chil. Chem. Soc. [online]. 2013, vol.58, n.4, pp.1982-1985. ISSN 0717-9707.  http://dx.doi.org/10.4067/S0717-97072013000400016.

The aim of this work is to study the sulfite oxidation mediated by glassy carbon electrodes modified with copolymers formed by ortho-phenylenediamine (OPD) and Co(II)-tetrakis(para-aminophenyl)porphyrin (CoTAPP). The copolymer was obtained through continuous cycling of potential of a glassy carbon electrode in acid medium containing each respective homopolymer in 1:1 feeding volume, in which the ortho-phenylenediamine concentration was 110^-1 M and the CoTAPP concentration was 110^-4 M. The film obtained is thin, stable and contains a low amount of porphyrin in comparison to the amount in ortho-phenylenediamine. Its electrocatalytic activity was tested toward the sulfite oxidation. In this case, this film is more electrocatalytic than the modified electrode modified with the CoTAPP electropolymer, even though ortho-phenylenediamine is inactive in this reaction. In this work the electrocatalysis process, the morphology of the film, and the difference of electrocatalytic behavior between the ortho-phenylenediamine and cobalt porphyrin homopolymers and the ortho-phenylenediamine-porphyrin copolymer were studied. The morphologic studies were done using Au electrodes since the electrocatalytic activity on Au and on glassy carbon are quite similar.

Keywords : conducting polymers; modified electrodes; electrocatalysis; copolymers; Co(II)-tetrakis(para-aminophenyl)porphyrin; ortho-phenylenediamine; oxidation of sulfite.

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