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Electrocatalytic Oxygen Reduction Reaction on Perovskite Oxides: Series versus Direct Pathway
Author(s) -
Poux Tiphaine,
Bonnefont Antoine,
Kéranguéven Gwénaëlle,
Tsirlina Galina A.,
Savinova Elena R.
Publication year - 2014
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201402022
Subject(s) - chemistry , perovskite (structure) , hydrogen peroxide , inorganic chemistry , catalysis , oxygen , hydrogen , oxide , carbon fibers , redox , peroxide , electrocatalyst , reversible hydrogen electrode , adsorption , electrode , materials science , electrochemistry , reference electrode , crystallography , organic chemistry , composite number , composite material
The mechanism of the oxygen reduction reaction (ORR) on LaCoO 3 and La 0.8 Sr 0.2 MnO 3 perovskite oxides is studied in 1 M NaOH by using the rotating ring disc electrode (RRDE) method. By combining experimental studies with kinetic modeling, it was demonstrated that on perovskite, as well as on perovskite/carbon electrodes, the ORR follows a series pathway through the intermediate formation of hydrogen peroxide. The escape of this intermediate from the electrode strongly depends on: 1) The loading of perovskite; high loadings lead to an overall 4 e − oxygen reduction due to efficient hydrogen peroxide re‐adsorption on the active sites and its further reduction. 2) The addition of carbon to the catalytic layer, which affects both the utilization of the perovskite surface and the production of hydrogen peroxide. 3) The type of oxide; La 0.8 Sr 0.2 MnO 3 displays higher (compared to LaCoO 3 ) activity in the reduction of oxygen to hydrogen peroxide and in the reduction/oxidation of the latter.