Insights into structure and dynamics of (Mn,Fe)Ox-promoted Rh nanoparticles
| العنوان: | Insights into structure and dynamics of (Mn,Fe)Ox-promoted Rh nanoparticles |
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| المؤلفون: | Ekkehard Schwab, Wolfgang Malzer, Jutta Kröhnert, Harry Kaiser, Christiane Janke, Christopher Schlesiger, Maria Dimitrakopoulou, Robert Schlögl, Stephan Andreas Schunk, Xing Huang, Detre Teschner, Annette Trunschke, Frank Rosowski, Sebastian Praetz |
| المصدر: | Faraday Discussions |
| بيانات النشر: | Royal Society of Chemistry (RSC), 2018. |
| سنة النشر: | 2018 |
| مصطلحات موضوعية: | X-ray absorption spectroscopy, Materials science, Absorption spectroscopy, Inorganic chemistry, chemistry.chemical_element, Infrared spectroscopy, 02 engineering and technology, Manganese, 010402 general chemistry, 021001 nanoscience & nanotechnology, 01 natural sciences, 0104 chemical sciences, Catalysis, chemistry, X-ray photoelectron spectroscopy, Physical and Theoretical Chemistry, Fourier transform infrared spectroscopy, 0210 nano-technology, Spectroscopy |
| الوصف: | The mutual interaction between Rh nanoparticles and manganese/iron oxide promoters in silica-supported Rh catalysts for the hydrogenation of CO to higher alcohols was analyzed by applying a combination of integral techniques including temperature-programmed reduction (TPR), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS) and Fourier transform infrared (FTIR) spectroscopy with local analysis by using high angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) in combination with energy dispersive X-ray spectroscopy (EDX). The promoted catalysts show reduced CO adsorption capacity as evidenced through FTIR spectroscopy, which is attributed to a perforated core-shell structure of the Rh nano-particles in accordance with the microstructural analysis from electron microscopy. Iron and manganese occur in low formal oxidation states between 2+ and zero in the reduced catalysts as shown by using TPR and XAS. Infrared spectroscopy measured in diffuse reflectance at reaction temperature and pressure indicates that partial coverage of the Rh particles is maintained at reaction temperature under operation and that the remaining accessible metal adsorption sites might be catalytically less relevant because the hydrogenation of adsorbed carbonyl species at 523 K and 30 bar hydrogen essentially failed. It is concluded that Rh0 is poisoned due to the adsorption of CO under the reaction conditions of CO hydrogenation. The active sites are associated either with a (Mn,Fe)Ox (x < 0.25) phase or species at the interface between Rh and its co-catalyst (Mn,Fe)Ox. |
| وصف الملف: | application/pdf |
| تدمد: | 1364-5498 1359-6640 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4f4fbab515a846387924b820040c5b6d https://doi.org/10.1039/c7fd00215g |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi.dedup.....4f4fbab515a846387924b820040c5b6d |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 13645498 13596640 |
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