|
|||||
|
|
Interaction of NO2 with Model NSR Catalysts: Metal–Oxide Interaction Controls Initial NOx Storage Mechanism |
|
| Authors: | Aine Desikusumastuti Thorsten Staudt Zhihui Qin Dr. Markus Happel Mathias Laurin Dr. Yaroslava Lykhach Dr. Shamil Shaikhutdinov Dr. Friedemann Rohr Dr. Jörg Libuda Prof. Dr. |
| Affiliation: | 1. Lehrstuhl für Physikalische Chemie II, Universit?t Erlangen‐Nürnberg, Egerlandstr. 3, 91058 Erlangen (Germany), Fax: (+49)?9131 8427308;2. Fritz‐Haber‐Institut der Max‐Planck‐Gesellschaft, Faradayweg 4‐6, 14195 Berlin (Germany);3. Current address: Research Centre for Spectrochemistry, The University of Tokyo, Hongo, Tokyo 113‐0033 (Japan);4. Umicore AG & Co. KG, Automotive Catalysts, Rodenbacher Chaussee 4, 63403 Hanau‐Wolfgang (Germany) |
| Abstract: | Using scanning tunneling microscopy (STM), molecular‐beam (MB) methods and time‐resolved infrared reflection absorption spectroscopy (TR‐IRAS), we investigate the mechanism of initial NOx uptake on a model nitrogen storage and reduction (NSR) catalyst. The model system is prepared by co‐deposition of Pd metal particles and Ba‐containing oxide particles onto an ordered alumina film on NiAl(110). We show that the metal–oxide interaction between the active noble metal particles and the NOx storage compound in NSR model catalysts plays an important role in the reaction mechanism. We suggest that strong interaction facilitates reverse spillover of activated oxygen species from the NOx storage compound to the metal. This process leads to partial oxidation of the metal nanoparticles and simultaneous stabilization of the surface nitrite intermediate. |
| Keywords: | heterogeneous catalysis IR spectroscopy model catalysts molecular beams reaction mechanisms |