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O: Fachverband Oberflächenphysik

O 40: Poster Tuesday: Adsorption and Catalysis

O 40.5: Poster

Dienstag, 2. April 2019, 18:00–20:00, Poster D

Structure evolution of oxide-supported Pt nanoparticles under reaction conditions — •Junjun Wang, Alexei Nefedov, Christof Wöll, and Yuemin Wang — Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany

Noble metal nanoparticles (e.g. Pt) dispersed on oxide supports have attracted great interest due to their high catalytic activity for various chemical reactions. Despite extensive investigations, a thorough understanding of the structure-activity relationship remains still a major challenge. In this work, the structure evolution of oxide-supported Pt nanoparticles (NPs) under different conditions was monitored by temperature-dependent infrared (IR) spectroscopy using CO as a probe molecule in combination with grazing-emission XPS. For Pt/CeO₂ it was found that Pt NPs vary substantially in size and oxidation state depending on the reductive/oxidative conditions. The IR data together with high-resolution TEM results obtained for Pt/Al₂O₃ catalysts revealed the presence of Pt particles/clusters with different shape and size ranging from isolated atoms to sub-nanometer clusters and ordered NPs. Our results allowed to gain deep insight into the structure evolution of various Pt species during the course of propane dehydrogenation reaction.