کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
56893 | 47099 | 2009 | 8 صفحه PDF | دانلود رایگان |
We have investigated the kinetics, rate oscillations and electrochemical promotion of CO oxidation on Pt deposited on YSZ using a standard oxygen reference electrode at temperatures 300–400 °C. We have found that electropromotion is small (ρ < 3) when the catalyst potential UWR, is below 0.4 V and very pronounced (ρ ∼ 9, Λ ∼ 1500) when UWR exceeds 0.4 V. This sharp transition in the electropromotion behavior is accompanied by an abrupt change in reaction kinetics and in catalyst potential. For fixed temperature this transition, which leads to a highly active electropromoted state, occurs at specific PO21/2/PCO ratio and catalyst potential. It is shown via comparison with independent catalyst potential–catalyst work function measurements that the transition corresponds to the onset of extensive O2− spillover from YSZ onto the catalyst surface, and concomitant establishment of an effective double layer at the catalyst–gas interface, which is the cause of the highly active electropromoted state.
Journal: Catalysis Today - Volume 146, Issues 3–4, 31 August 2009, Pages 351–358