Publication Date:
2017-01-23
Description:
Publication date: 20 February 2017 Source: Electrochimica Acta, Volume 228 Author(s): Ilena Grimmer, Paul Zorn, Stephan Weinberger, Christoph Grimmer, Birgit Pichler, Bernd Cermenek, Florian Gebetsroither, Alexander Schenk, Franz-Andreas Mautner, Brigitte Bitschnau, Viktor Hacker La 0.7 Sr 0.3 (Fe 0.2 Co 0.8 )O 3 and La 0.7 Sr 0.3 MnO 3 −based cathode catalysts are synthesized by the sol-gel method. These perovskite cathode catalysts are tested in half cell configuration and compared to MnO 2 as reference material in alkaline direct ethanol fuel cells (ADEFCs). The best performing cathode is tested in single cell setup using a standard carbon supported Pt 0.4 Ru 0.2 based anode. A backside Luggin capillary is used in order to register the anode potential during all measurements. Characteristic processes of the electrodes are investigated using electrochemical impedance spectroscopy. Physical characterizations of the perovskite based cathode catalysts are performed with a scanning electron microscope (SEM) and by X-ray diffraction showing phase pure materials. In half cell setup, La 0.7 Sr 0.3 MnO 3 shows the highest tolerance toward ethanol with a performance of 614 mA cm −2 at 0.65 V vs. RHE in 6 M KOH and 1 M EtOH at RT. This catalyst outperforms the state-of-the-art precious metal-free MnO 2 catalyst in presence of ethanol. In fuel cell setup, the peak power density is 27.6 mW cm −2 at a cell voltage of 0.345 V and a cathode potential of 0.873 V vs. RHE. Graphical abstract
Print ISSN:
0013-4686
Electronic ISSN:
1873-3859
Topics:
Chemistry and Pharmacology
,
Physics
