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Enhancing Electrochemical Water‐Splitting Kinetics by Polarization‐Driven Formation of Near‐Surface Iron(0): An In Situ XPS Study on Perovskite‐Type Electrodes
Author(s) -
Opitz Alexander K.,
Nenning Andreas,
Rameshan Christoph,
Rameshan Raffael,
Blume Raoul,
Hävecker Michael,
KnopGericke Axel,
Rupprechter Günther,
Fleig Jürgen,
Klötzer Bernhard
Publication year - 2015
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201409527
Subject(s) - x ray photoelectron spectroscopy , water splitting , dielectric spectroscopy , polarization (electrochemistry) , electrolysis , cathode , electrode , electrochemistry , electrolysis of water , materials science , inorganic chemistry , chemistry , analytical chemistry (journal) , chemical engineering , catalysis , photocatalysis , biochemistry , engineering , chromatography , electrolyte
In the search for optimized cathode materials for high‐temperature electrolysis, mixed conducting oxides are highly promising candidates. This study deals with fundamentally novel insights into the relation between surface chemistry and electrocatalytic activity of lanthanum ferrite based electrolysis cathodes. For this means, near‐ambient‐pressure X‐ray photoelectron spectroscopy (NAP‐XPS) and impedance spectroscopy experiments were performed simultaneously on electrochemically polarized La 0.6 Sr 0.4 FeO 3− δ (LSF) thin film electrodes. Under cathodic polarization the formation of Fe 0 on the LSF surface could be observed, which was accompanied by a strong improvement of the electrochemical water splitting activity of the electrodes. This correlation suggests a fundamentally different water splitting mechanism in presence of the metallic iron species and may open novel paths in the search for electrodes with increased water splitting activity.