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Technical University of Crete
Technical University of Crete
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| URI: | http://purl.tuc.gr/dl/dias/52AF71A8-1CEC-44B5-9E75-8B3D07050483 | ||
| Year | 1994 | ||
| Type of Item | Peer-Reviewed Journal Publication | ||
| License |
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| Bibliographic Citation | I. V. Yentekakis, G. Moggridge, C. G. Vayenas and R. M. Lambert, "In Situ controlled promotion of catalyst surfaces via NEMCA: The effect of Na on the Pt-catalyzed CO oxidation", J. Catal., vol. 146, no. 1, pp. 292-305, Mar. 1994. doi:10.1016/0021-9517(94)90033-7 https://doi.org/10.1016/0021-9517(94)90033-7 | ||
| Appears in Collections |
It was found that the catalytic activity of Pt for CO oxidation can be markedly and reversibly affected by depositing polycrystalline Pt films on β″-Al2O3, a Na+ conductor, and applying external potentials to supply or remove Na to or from the Pt catalyst surface. The change in the rate of CO oxidation is typically 103-105 times larger than the rate of supply or removal of Na. The use of the β″-Al2O3 solid electrolyte supports permits precise in situ control of the Na coverage on the Pt surface. Sodium coverages of 0.02 cause up to 600% steady-state increase in the rate of CO oxidation under CO-rich conditions. The promoting effect is due to enhanced oxygen chemisorption on the Pt surface. Higher (>0.06) Na coverages poison the rate severely and reversibly due to the formation of a CONaPt surface complex. Rate oscillations can be reversibly induced or stopped and their frequency can be controlled by controlling the catalyst potential VWR and average work function eφ.
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