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O: Fachverband Oberflächenphysik
O 33: Poster: Supported Nanoclusters and Catalysis
O 33.1: Poster
Tuesday, March 19, 2024, 18:00–20:00, Poster C
HR-XPS Study on the Adsorption of CO on Graphene-Supported Co Clusters — •Natalie Waleska-Wellnhofer1, Fabian Düll1, Udo Bauer1, Phillip Bachmann1, Johann Steinhauer1, and Christian Papp1, 2 — 1Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany — 2Freie Universität Berlin, Germany
Cobalt plays an important role as catalytic active material for the industrial production of hydrocarbons by Fischer-Tropsch synthesis. To overcome the material gap, we investigated graphene-supported Co clusters as model catalyst by HR-XPS to gather more information about the catalysts' properties. Using CO as a probe molecule, we were able to determine the available adsorption sites on the as-prepared clusters which are edge/top and bridge/hollow sites. The desorption temperatures of CO from these sites were determined by temperature-programmed XPS to be 360 and 240 K, respectively. Additionally, CO dissociation was observed. The dissociation products were used to study the influence of C and O on the reactivity of the clusters. For the precovered clusters, no CO adsorption at edge sites was observed due to site blocking. Furthermore, no CO dissociation was found. Thus, the edge sites are determined to be the most active sites. Moreover, the desorption temperature of CO decreased as a result of a change in the adsorption energy on the precovered clusters.
We thank Helmholtz-Zentrum Berlin for allocation of beamtime and BESSY II staff for support during beamtime. This work was funded by the DFG within SFB 953.
Keywords: XPS; Cobalt; Graphene; CO Adsorption