[Zurück]

A.K. Opitz, A. Nenning, Ch. Rameshan, R. Rameshan, R. Blume, M. Hävecker, A. Knop-Gericke, G. Rupprechter, J. Fleig, B. Klötzer:
"Improving electrochemical water-splitting kinetics by polarization-driven formation of near-surface Fe0: An in-situ XPS study on perovskite-type electrodes";
Angewandte Chemie - International Edition, 54 (2015), S. 2628 - 2632.

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 La0.6Sr0.4FeO3 d (LSF) thin film
electrodes. Under cathodic polarization the formation of Fe0 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.

http://dx.doi.org/10.1002/anie.201409527

http://publik.tuwien.ac.at/files/PubDat_237575.pdf