Oxygen reduction on a ruthenium electrode in alkaline electrolytes
Abstract
The kinetics of oxygen reduction have been studied on a ruthenium electrode in alkaline solutions using the rotating disc and rotating disc-ring methods. The reaction kinetics and mechanism were found to depend on the oxidation state of the ruthenium surface. For a surface having up to two monolayers of oxide a "parallel" mechanism of O2 reduction has been found, which goes predominantly through a four-electron direct reduction to OH-. All the rate constants of the O2 and HO-2 reactions, including those of the adsorption equilibrium of HO-2 on the Ru surface, have been determined. No catalytic decomposition of HO-2 was found. Although the Tafel slope is higher than -120 mV/dec it appears that an initial electron exchange is the rate-determining step. The kinetics are slower on a Ru surface with a thicker oxide layer. The mechanism of the reaction is also different, showing a potential-dependent ratio of the rate constants for a direct and series reduction of O2 and a catalytic decompos...ition of HO-2.
Keywords:
oxygen reduction / ruthenium / Kinetics / ruthenium electrode / rotating disc method / rotating disc-ring methodSource:
Journal of Electroanalytical Chemistry, 1986, 199, 2, 351-364Publisher:
- Elsevier
Funding / projects:
- Research Fund of SR Serbia, Yugoslavia
- The National Science Foundation, U.S.A., Contract No. 471
DOI: 10.1016/0022-0728(86)80009-2
ISSN: 0022-0728; 1572-6657
Scopus: 2-s2.0-33750140996
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Institution/Community
IHTMTY - JOUR AU - Anastasijević, Nikola A. AU - Dimitrijević, Z. M. AU - Adžić, Radoslav R. PY - 1986 UR - https://cer.ihtm.bg.ac.rs/handle/123456789/4200 AB - The kinetics of oxygen reduction have been studied on a ruthenium electrode in alkaline solutions using the rotating disc and rotating disc-ring methods. The reaction kinetics and mechanism were found to depend on the oxidation state of the ruthenium surface. For a surface having up to two monolayers of oxide a "parallel" mechanism of O2 reduction has been found, which goes predominantly through a four-electron direct reduction to OH-. All the rate constants of the O2 and HO-2 reactions, including those of the adsorption equilibrium of HO-2 on the Ru surface, have been determined. No catalytic decomposition of HO-2 was found. Although the Tafel slope is higher than -120 mV/dec it appears that an initial electron exchange is the rate-determining step. The kinetics are slower on a Ru surface with a thicker oxide layer. The mechanism of the reaction is also different, showing a potential-dependent ratio of the rate constants for a direct and series reduction of O2 and a catalytic decomposition of HO-2. PB - Elsevier T2 - Journal of Electroanalytical Chemistry T1 - Oxygen reduction on a ruthenium electrode in alkaline electrolytes VL - 199 IS - 2 SP - 351 EP - 364 DO - 10.1016/0022-0728(86)80009-2 ER -
@article{ author = "Anastasijević, Nikola A. and Dimitrijević, Z. M. and Adžić, Radoslav R.", year = "1986", abstract = "The kinetics of oxygen reduction have been studied on a ruthenium electrode in alkaline solutions using the rotating disc and rotating disc-ring methods. The reaction kinetics and mechanism were found to depend on the oxidation state of the ruthenium surface. For a surface having up to two monolayers of oxide a "parallel" mechanism of O2 reduction has been found, which goes predominantly through a four-electron direct reduction to OH-. All the rate constants of the O2 and HO-2 reactions, including those of the adsorption equilibrium of HO-2 on the Ru surface, have been determined. No catalytic decomposition of HO-2 was found. Although the Tafel slope is higher than -120 mV/dec it appears that an initial electron exchange is the rate-determining step. The kinetics are slower on a Ru surface with a thicker oxide layer. The mechanism of the reaction is also different, showing a potential-dependent ratio of the rate constants for a direct and series reduction of O2 and a catalytic decomposition of HO-2.", publisher = "Elsevier", journal = "Journal of Electroanalytical Chemistry", title = "Oxygen reduction on a ruthenium electrode in alkaline electrolytes", volume = "199", number = "2", pages = "351-364", doi = "10.1016/0022-0728(86)80009-2" }
Anastasijević, N. A., Dimitrijević, Z. M.,& Adžić, R. R.. (1986). Oxygen reduction on a ruthenium electrode in alkaline electrolytes. in Journal of Electroanalytical Chemistry Elsevier., 199(2), 351-364. https://doi.org/10.1016/0022-0728(86)80009-2
Anastasijević NA, Dimitrijević ZM, Adžić RR. Oxygen reduction on a ruthenium electrode in alkaline electrolytes. in Journal of Electroanalytical Chemistry. 1986;199(2):351-364. doi:10.1016/0022-0728(86)80009-2 .
Anastasijević, Nikola A., Dimitrijević, Z. M., Adžić, Radoslav R., "Oxygen reduction on a ruthenium electrode in alkaline electrolytes" in Journal of Electroanalytical Chemistry, 199, no. 2 (1986):351-364, https://doi.org/10.1016/0022-0728(86)80009-2 . .