Inhaltszusammenfassung

The electrochemical promotion of the C(2)H(4)+O(2) reaction to form CO(2) and H(2)O is studied in the 10(-5) and 10(-4) mbar range with a Pt catalyst interfaced as working electrode to yttrium-stabilized zirconia (YSZ). Photoemission electron microscopy (PEEM) was used as spatially resolving method. Under open-circuit conditions, that is, without an external voltage applied, the CO(2) production exhibits a pronounced hysteresis upon cyclic variation of p(C(2)H(4)). The hysteresis is attribute...The electrochemical promotion of the C(2)H(4)+O(2) reaction to form CO(2) and H(2)O is studied in the 10(-5) and 10(-4) mbar range with a Pt catalyst interfaced as working electrode to yttrium-stabilized zirconia (YSZ). Photoemission electron microscopy (PEEM) was used as spatially resolving method. Under open-circuit conditions, that is, without an external voltage applied, the CO(2) production exhibits a pronounced hysteresis upon cyclic variation of p(C(2)H(4)). The hysteresis is attributed to the build-up of a carbonaceous CH(x) layer inhibiting O(2) adsorption and hence poisoning the reaction. It is shown that the application of a positive potential of 1 V triggers a transition from the unreactive branch of the reaction to an active branch. The large non-Faradayicity reported in the literature for this reaction system is explained as an ignition effect caused by the partial removal of the inhibiting carbonaceaous layer. » weiterlesen» einklappen

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