- Title
- Volcano correlations for the reactivity of surface-confined cobalt N4-macrocyclics for the electrocatalytic oxidation of 2-mercaptoacetate
- Creator
- Claußen, Jan A, Ochoa, Gonzalo, Páez, Maritza, Costamagno, Juan, Gulppi, Miguel, Nyokong, Tebello, Bedioui, Fethi, Zagal, José H
- Subject
- To be catalogued
- Date
- 2008
- Type
- text
- Type
- article
- Identifier
- http://hdl.handle.net/10962/268688
- Identifier
- vital:54222
- Identifier
- xlink:href="https://doi.org/10.1007/s10008-007-0336-y"
- Description
- We have investigated the electrocatalytic activity of several substituted and unsubstituted cobalt–phthalocyanines of substituted tetraphenyl porphyrins and of vitamin B12, for the electro-oxidation of 2-mercaptoacetate, with the complexes pre-adsorbed on a pyrolytic graphite electrode. Several N4-macrocyclic were used to have a wide variety of Co(II)/(I) formal potentials. The electrocatalytic activity, measured as current at constant potential, increases with the Co(II)/(I) redox potential for porphyrins as Co–pentafluorotetraphenylporphyrin larger than Co–tetrasulfonatotetraphenylporphyrin larger than Co-2,2′,2″,2‴tetra-aminotetraphenylporphyrin and decreases for cobalt phthalocyanines as Co-3,4-octaethylhexyloxyphthalocyanine > Co–octamethoxyphthalocyanine > Co–tetranitrophthalocyanine Co–tetraaminophthalocyanine > Co–unsubstituted phthalocyanine > Co–tetrasulfonatophthalocyanine > Co–perfluorinated phthalocyanine. Vitamin B12 exhibits the maximum activity. A correlation of log I (at constant potential) versus the Co(II)/(I) formal potential of the catalysts gives a volcano curve. This clearly shows that the search for better catalysts for this reaction point to those N4-macrocyclic complexes with Co(II)/(I) formal potentials close to −0.84 V versus SCE, which correspond to an optimum situation for the interaction of the thiol with the active site.
- Format
- computer, online resource, application/pdf, 1 online resource (9 pages), pdf
- Publisher
- SpringerLink
- Language
- English
- Relation
- Journal of Solid State Electrochemistry, Claußen, J.A., Ochoa, G., Páez, M., Costamagna, J., Gulppi, M., Nyokong, T., Bedioui, F. and Zagal, J.H., 2008. Volcano correlations for the reactivity of surface-confined cobalt N4-macrocyclics for the electrocatalytic oxidation of 2-mercaptoacetate. Journal of Solid State Electrochemistry, 12(5), pp.473-481, Journal of Solid State Electrochemistry volume 12 number 5 p. 473 2008 1433-0768
- Rights
- Publisher
- Rights
- Use of this resource is governed by the terms and conditions of the SpringerLink Terms of Use Statement ( https://link.springer.com/termsandconditions)
- Rights
- Open Access
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Nyokong, Tebello (Distinguished Professor)
RU DST/NRF SARChI for Medicinal Chemistry and Nanotechnology
RU Department of Chemistry
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