Premium
Oxygen Reduction at Carbon‐Supported Lanthanides: The Role of the B‐Site
Author(s) -
Celorrio Verónica,
Dann Ellie,
Calvillo Laura,
Morgan David J.,
Hall Simon R.,
Fermin David J.
Publication year - 2016
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201500440
Subject(s) - carbon fibers , oxygen , electrochemistry , redox , lanthanide , chemistry , catalysis , reactivity (psychology) , oxygen reduction , inorganic chemistry , ionic bonding , oxygen reduction reaction , faraday efficiency , transition metal , decoupling (probability) , electrode , materials science , organic chemistry , ion , medicine , alternative medicine , pathology , composite number , composite material , control engineering , engineering
The kinetics of the oxygen reduction reaction (ORR) at carbon‐supported transition‐metal oxides in alkaline solutions is systematically investigated as a function of the nature of the B‐site. The study is focused on LaBO 3 (B=Cr, Co, Fe, Mn and Ni) nanoparticles synthesized by using an ionic‐liquid route, offering fine control over phase purity and composition. Activity towards the ORR was compared with the commercial Pt/Etek catalyst. Detailed electrochemical analysis employing a rotating ring‐disk electrode provides conclusive evidence that the carbon support plays an important contribution in the faradaic responses. Decoupling the contribution of the carbon support uncovers that the reactivity of LaMnO 3 towards the four‐electron ORR pathway is orders of magnitude higher than that for the other lanthanides. We rationalize these observations in terms of changes in the redox state at the B‐site close to the formal oxygen reduction potential.