Oscillations in the Carbon Monoxide Oxidation on Platinum Surfaces Observed by Field Electron Microscopy Full article
Conference |
39th International Field Emission Symposium 10-14 Aug 1992 , Halifax, Nova Scotia |
||||
---|---|---|---|---|---|
Journal |
Applied Surface Science
ISSN: 0169-4332 |
||||
Output data | Year: 1993, Volume: 67, Number: 1-4, Pages: 198-205 Pages count : 8 DOI: 10.1016/0169-4332(93)90312-Y | ||||
Tags | catalytic CO oxidation; kinetic oscillation; Pt(110) surface | ||||
Authors |
|
||||
Affiliations |
|
Funding (3)
1 | German Research Foundation | SFB 6/81 |
2 | Max Planck Society | |
3 | Society for Chemical Engineering and Biotechnology |
Abstract:
Platinum field emitter tips ((111)-, (001)-, and (012)-oriented) are used to investigate local surface properties during the oscillatory regime of the CO-oxidation at T = 430–480 K and partial pressures po2≈5×10-4 mbar and pCO≈5×10-5 mbar. Changes in surface coverage - and catalytic activity - are indicated by variations of the local work function and field emission current. Self-sustaining isothermal oscillations could be observed on different crystal planes. (i) A fast “switching on” of emission currents is initially noticed when the oxygen adsorption layer is transferred into a CO-layer. Starting - after a certain induction period - from the (011)-region the oxygen side is quickly switched into the CO-side, which slowly returns back to the catalytically active oxygen side. (ii) The formation of reactive wave fronts starts in the (011)-region and propagates in the direction of (111)- and (100)-planes. The CO-wavefront and the
O-wavefront move alternately in opposite directions and display different propagation velocities, which could be measured. The frequencies and amplitudes of oscillations critically depends on temperatures and partial pressures. Compared to single crystal planes a broadening and shift of oscillatory regimes in parameter space is noticed. In certain cases period doubling could be measured.
Cite:
Gorodetskii V.
, Block J.H.
, Drachsel W.
, Ehsasi M.
Oscillations in the Carbon Monoxide Oxidation on Platinum Surfaces Observed by Field Electron Microscopy
Applied Surface Science. 1993. V.67. N1-4. P.198-205. DOI: 10.1016/0169-4332(93)90312-Y WOS Scopus РИНЦ
Oscillations in the Carbon Monoxide Oxidation on Platinum Surfaces Observed by Field Electron Microscopy
Applied Surface Science. 1993. V.67. N1-4. P.198-205. DOI: 10.1016/0169-4332(93)90312-Y WOS Scopus РИНЦ
Dates:
Submitted: | Aug 10, 1992 |
Accepted: | Aug 28, 1992 |
Published print: | Apr 2, 1993 |
Published online: | Aug 5, 2002 |
Identifiers:
Web of science | WOS:A1993KZ64700031 |
Scopus | 2-s2.0-0027224865 |
Elibrary | 31104067 |
Chemical Abstracts | 1993:241598 |
Chemical Abstracts (print) | 118:241598 |
OpenAlex | W2092304857 |