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O: Fachverband Oberflächenphysik

O 51: Surface chemical reactions I

O 51.7: Vortrag

Donnerstag, 26. März 2009, 17:45–18:00, SCH A01

Interaction of Thin Nickel Oxide Layers with Carbon Oxides — •Michael Peter Andreas Lorenz¹, Regine Streber¹, Christian Papp¹, Marie-Madeleine Walz¹, Andreas Bayer¹, Sandra Künzel², Reinhard Denecke², and Hans-Peter Steinrück¹ — ¹Lehrstuhl für Physikalische Chemie II, Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen — ²Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstr. 2, 04103 Leipzig

NiO is an important material in heterogeneous catalysis. Under ambient conditions, reaction with CO₂ can easily lead to the formation of carbonates, which could block active sites and thereby influence the catalytic reactivity. Behm and Brundle [1] reported carbonate formation on Ni(100) by simultaneously dosing molecular oxygen and CO₂. We have now studied the interaction of CO₂ and also CO on an oxidised Ni(111) surface in great detail by in situ XPS applying synchrotron radiation at BESSY II. For both, characteristic peaks develop in the O 1s and C 1s spectra, albeit with different intensities, indicating the formation of carbonate layers. Similar results are obtained for thick oxidised Ni layers (∼2 ML) grown on Cu(111). In contrast, thin oxidised Ni layers (∼0.5 ML) on Cu(111) exhibit a significantly reduced reactivity towards carbonate formation. The decomposition of the carbonate species was determined in situ by XPS during heating. This work was supported by BMBF (05 ES3XBA/5) and the DFG through the Cluster of Excellence "Engineering of Advanced Materials".
R. J. Behm, C. R. Brundle, Surf. Sci. 255 (1991) 327