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The Electrochemical Promotion of Ethylene Oxidation at a Pt/YSZ Catalyst
Author(s) -
Toghan Arafat,
Rösken Liz M.,
Imbihl Ronald
Publication year - 2010
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.200900936
Subject(s) - catalysis , ethylene , electrochemistry , yttria stabilized zirconia , platinum , chemistry , materials science , photochemistry , inorganic chemistry , organic chemistry , electrode , cubic zirconia , ceramic
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.