Aerobic oxidation of alcohols over Ru-Mn-Ce and Ru-Co-Ce catalysts: The effect of calcination temperature
| Autor: | Ran Miao, Curtis Guild, Wenxiu Li, Steven L. Suib, David A. Kriz, Fang Wang, Junkai He, Jing Jin, Gui Liu, Junhua Liu, Cheng Liu |
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| Rok vydání: | 2017 |
| Předmět: |
Process Chemistry and Technology
Inorganic chemistry chemistry.chemical_element Infrared spectroscopy 02 engineering and technology Manganese 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Oxygen Catalysis 0104 chemical sciences law.invention Ruthenium X-ray photoelectron spectroscopy chemistry law Alcohol oxidation Calcination 0210 nano-technology |
| Zdroj: | Applied Catalysis A: General. 535:77-84 |
| ISSN: | 0926-860X |
| Popis: | Two ternary mixed oxides, Ru-Mn-Ce and Ru-Co-Ce, were prepared by a co-precipitation method and used in the aerobic oxidation of alcohols to corresponding aldehydes (ketones). Interestingly, different catalytic results were obtained when these compounds were calcined. The calcination temperature had an adverse effect on the catalytic performance of Ru-Mn-Ce catalysts, while being beneficial to the Ru-Co-Ce catalysts. To illustrate these effects, these materials were characterized using X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Temperature-programmed reduction (TPR), Electron paramagnetic resonance (EPR) and other techniques. The data showed that ruthenium oxides were uniformly dispersed in the mixed oxides, and phase transformations occur after calcination. Mn3O4 was transformed to MnO2 for the Ru-Mn-Ce catalyst, while CoO(OH) was transformed to Co3O4 in the Ru-Co-Ce catalyst. The interactions between ruthenium oxides and Co (Mn)-Ce mixed oxides of the former strengthened while the latter weakened. Calcination decreased the content of adsorbed oxygen and restricted oxygen transfer mechanism in the manganese system, while the opposite effect was observed with the cobalt-containing catalyst. Under optimal reaction conditions, various kinds of alcohols were transformed to corresponding aldehydes (ketones) in high yields over the Ru-Mn-Ce catalyst suggesting these ternary oxides are environmental friendly and economical catalytic systems. |
| Databáze: | OpenAIRE |
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