Efficiency of manganese modified CTAB-templated ceria-zirconia catalysts in total CO oxidation
| Autor: | A. V. Fionov, Konstantin I. Maslakov, Oksana Ya. Isaikina, Elena V. Golubina, Valery V. Lunin, Ekaterina S. Lokteva, Igor Yu. Kaplin, V.V. Shishova |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
Inorganic chemistry Oxide General Physics and Astronomy chemistry.chemical_element 02 engineering and technology Surfaces and Interfaces General Chemistry Manganese Crystal structure 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Redox 0104 chemical sciences Surfaces Coatings and Films Catalysis chemistry.chemical_compound Adsorption chemistry X-ray photoelectron spectroscopy Specific surface area 0210 nano-technology |
| Zdroj: | Applied Surface Science. 485:432-440 |
| ISSN: | 0169-4332 |
| DOI: | 10.1016/j.apsusc.2019.04.206 |
| Popis: | CTAB templated Ce0.8Zr0.2O2 (CZ), MnOx-Ce0.8Zr0.2O2 (Mn-CZ), CeO2 and MnOx oxide catalysts were prepared by precipitation and tested in CO oxidation. Manganese was added to CZ oxide at the precipitation stage (Mn-CZ) or by impregnation of the precipitated CZ oxide with manganese salt (Mn-CZ IM). Despite the decrease in the specific surface area after modification with Mn, both Mn-modified catalysts showed the significant improvement in the catalytic performance. Mn-CZ IM exhibited better catalytic activity than Mn-CZ, which was explained by the different distribution of manganese in CZ found by the complex SEM-EDS, XRD, TPR, Raman spectroscopy, XPS, and EPR study. In Mn-CZ both Mn2+ and Mn3+ ions are incorporated into the CZ lattice and form particles of MnOx phases uniformly distributed over the surface and in the bulk of CZ. In contrast, in Mn-CZ IM no manganese ions are embedded into the crystal lattice of CZ, while the surface of Mn-CZ IM comprises local areas mainly formed by CZ or MnOx. Such arrangement provides the additional adsorption sites and the second redox pair (Mn3+/Mn2+) in addition to Ce3+/Ce4+, improving low-temperature efficiency, whereas the surface areas depleted with MnOx serve as a source of the active oxygen from the CZ lattice, enhancing CO oxidation at high temperatures. |
| Databáze: | OpenAIRE |
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