| AVS 54th International Symposium | |
| Surface Science | Tuesday Sessions |
| Session SS1-TuM |
| Session: | Catalytic Chemistry of Hydrocarbons |
| Presenter: | J.N. Andersen, Lund University, Sweden |
| Authors: | J.N. Andersen, Lund University, Sweden E. Lundgren, Lund University, Sweden A. Resta, Lund University, Sweden |
| Correspondent: | Click to Email |
We have used high resolution core level photoemission to study how the adsorption, fragmentation, and reaction of ethylene and ethanol are influenced by low coordinated atoms found at the steps of vicinal Rh surfaces. The talk is naturally divided in two parts. In part 1, we describe how detailed analysis of the C1s spectra including the vibrational fine-structure of this level often facilitates determination of the adsorbed fragments of these molecules. In part 2, we use this method of identification to monitor the influence of steps. This was done by comparing results from Rh(111) and some of its vicinals. For ethanol adsorption, we find large differences in the fragmentation pattern at 300K between the Rh(111) and the Rh(553) surfaces, in particular, the steps on Rh(553) are found to be very effective in dehydrogenation reactions. We also find differences in the oxidation of ethanol, where Rh(553) is found to be more reactive. For ethylene adsorption we have studied the temperature induced ethylidyne formation and subsequent decomposition. Also in this case do we find that the steps increase the reactivity regarding fundamental reactions involved in both the formation and the decomposition pathways. In addition, comparison between Rh(553) and Rh(322) demonstrated a larger reactivity of (100)-type than of (111)-type micro-facets. Finally, we discuss the importance of the present results in the context of catalytic reactions on small metal particles.