Berlin 2015 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 17: Postersession I

MM 17.6: Poster

Monday, March 16, 2015, 18:00–20:00, Poster E

Optimized Pd/TiO₂ interfaces for high resolution TEM-EELS in H₂ atmosphere — •Marian Bongers, Carsten Nowak, and Astrid Pundt — Institut für Materialphysik, Georg-August-Universität Göttingen, Germany

Redox reactions on supported metal catalysts exhibit high turnover rates [1, 2]. The used support strongly influences the turnover rate and, therefore, the metal/support interface is expected to be a very important parameter. Atomic resolution STEM and EELS allow to investigate the electronic states at Pd/TiO₂ interfaces, which are expected to change under hydrogen atmosphere as suggested by Kobayashi et al. [3], thus eventually giving insight into the enhanced turnover rates.

Here we report on the preparation of optimized Pd/TiO₂ double layers. The layers were deposited by magnetron sputtering. XRD and texture measurements reveal epitaxial growth of a strained Pd-film on a single crystalline TiO₂ film.

EELS investigations on the electronic states in the vicinity of the Pd/TiO₂ interface are presented. Changes of the electronic states related to the presence of hydrogen are discussed. Additional EELS measurements on the oxygen edge show a strong dependency of the signal/noise ratio on the lamella thickness.

[1] D.C. Grenoble, M.M. Estadt, Journal of Catalysis 67 (1981) 90; [2] M. Bowker et al., Surface Science 497 (2002) 155; [3] H. Kobayashi et al., Surface Science 304 (1994) 393

Financial support by the DFG via SFB1073-C06 and DFG-PU131/9-1 is gratefully acknowledged.