Thiele, Doreen 2010-08-13 This work shows the stepwise improvement of air electrodes by the right combination of catalysts. In all electrodes carbon nanotubes serve as carbon support. The electrodes are produced by ultrasonic mixing of the carbon nanotubes and the catalysts. Their catalytic activity towards oxygen reduction in alkaline solution is evaluated by polarisation curves and electrochemical impedance spectroscopy. In a first step La_1−<i>x</i>Sr_<i>x</i>MnO₃ perovskites are investigated, as well as La_0.65Sr_0.35MnO₃ and La_0.6Sr_0.4CoO₃ are compared. It is found that La_0.65Sr_0.35MnO₃ and La_0.6Sr_0.4CoO₃ have a positive impact on different parts of the current–potential curve. In a second step the influence of small amounts of platinum as an additional catalyst besides the perovskite is analyzed with the result that platinum lowers significantly the activation polarisation. Finally, the optimum composition of the electrode is found by using the synergetic effect of platinum, La_0.65Sr_0.35MnO₃ and La_0.6Sr_0.4CoO₃.<strong>Keywords: </strong>Ceramics; Composite materials; Nanostructures; Electrochemical properties application/pdf https://folia.unifr.ch/global/documents/301690 https://folia.unifr.ch/documents/301690/files/thi_cpp.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1016/j.matchemphys.2010.07.005 info:eu-repo/semantics/openAccess License undefined Materials Chemistry and Physics. - 2010, vol. 124, no. 1, p. 529-534 Ceramics Composite materials Nanostructures Electrochemical properties info:eu-repo/classification/udc/53 Combined platinum/perovskite catalyst for an efficient nanostructured air electrode http://purl.org/coar/resource_type/c_6501