The structure and catalytic properties of Rh‐doped CeO2 catalysts
The average structure and the local structure of nanocrystalline Rh-doped CeO2 catalysts, prepared using a co-precipitation method, were studied using a set of structural (PDF, HRTEM, XRD) and spectral (XPS, Raman spectroscopy) methods. The samples with Rh content less than 10 wt%, calcined at 450 °...
| Published in: | Physical chemistry chemical physics Vol. 19, № 47. P. 31883-31897 |
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| Other Authors: | , , , , , , , |
| Format: | Article |
| Language: | English |
| Subjects: | |
| Online Access: | https://vital.lib.tsu.ru/vital/access/manager/Repository/koha:001157865 Перейти в каталог НБ ТГУ |
| Summary: | The average structure and the local structure of nanocrystalline Rh-doped CeO2 catalysts, prepared using a co-precipitation method, were studied using a set of structural (PDF, HRTEM, XRD) and spectral (XPS, Raman spectroscopy) methods. The samples with Rh content less than 10 wt%, calcined at 450 °C, were homogeneous solid solutions. A comparison of the experimental results and Pair distribution function (PDF) modeling data showed that Rh3+ substitutes Ce4+ ions in the fluorite phase. Charge equilibrium is obtained by the oxygen vacancy for each Rh3+ cation introduced into the ceria cell. The solid solution demonstrated high catalytic activity in low-temperature CO oxidation (LTO CO). The solid solutions were stable only in a nanocrystalline state and decomposed upon thermal treatment. The calcination of the solid solution at T > 450 °C results in a decrease in the catalytic activity that is accompanied by Rh association in the subsurface area and strong distortion of the anionic subcell. At T = 800 °C α-Rh2O3 nanoparticles are formed on the surface of the fluorite phase. The XRD-detectable Rh oxide phases are formed after calcination at 1000 °C. However, some parts of Rh within the subsurface RhxCe1-xO2-δ solid solution remain and they preserve catalytic properties for low-temperature oxidation. © 2017 the Owner Societies. |
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| Bibliography: | Библиогр.: 74 назв. |
| ISSN: | 1463-9076 |
| Access: | Ограниченный доступ |