Gleichweit C, Neiß C, Maisel S, Bauer U, Späth F, Höfert O, Görling A, Steinrück HP, Papp C (2017)
Publication Status: Published
Publication Type: Journal article
Publication year: 2017
Publisher: AMER CHEMICAL SOC
Book Volume: 121
Pages Range: 3133-3142
Journal Issue: 5
The adsorption and reaction of CO on a monolayer carbide and a bulk carbide, prepared on Mo(110), was studied with synchrotron-based XPS, TPD, and density-functional calculations using slab models. In the experiments on the monolayer carbide, we find two CO species at 140 K, with a saturation coverage of similar to 0.7 ML, while on the bulk carbide, Mo2C, three molecular adsorption states are found, showing a similar total coverage of similar to 0.7 ML at saturation. In addition, CO partly dissociates on both surfaces (monolayer carbide: 7%, bulk carbide: 15%). The calculations on the monolayer carbide show that the adsorption of CO on Mo sites is most stable. At increased coverages, several different adsorption sites on the monolayer carbide become possible. From the core level shifts, an assignment to the experimentally found species becomes available. Upon heating, we find on both carbides the competing processes of desorption, interconversion of different CO species, and dissociation of CO. The detailed quantitative analysis of these processes shows that desorption and dissociation to atomic oxygen and carbon is completed at similar to 400 K on the monolayer carbide and similar to 450 K on the bulk carbide; in both cases, about 35% (0.25 ML) of the initially adsorbed CO decomposes upon heating. Above 800 K, atomic carbon and oxygen desorb associatively, and at 1200 K the carbide surfaces are restored.
APA:
Gleichweit, C., Neiß, C., Maisel, S., Bauer, U., Späth, F., Höfert, O.,... Papp, C. (2017). Surface Reaction of CO on Carbide-Modified Mo(110). Journal of Physical Chemistry C, 121(5), 3133-3142. https://dx.doi.org/10.1021/acs.jpcc.6b11950
MLA:
Gleichweit, Christoph, et al. "Surface Reaction of CO on Carbide-Modified Mo(110)." Journal of Physical Chemistry C 121.5 (2017): 3133-3142.
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