Synthesis of Ca-doped spinel by Ultrasonic Spray Pyrolysis
| Autor: | Q. Jacques, M.T.T. Camargo, Lorena Batista Caliman, Douglas Gouvêa, Joice Miagava, Dachamir Hotza, Ricardo H. R. Castro |
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| Rok vydání: | 2016 |
| Předmět: |
Materials science
Scanning electron microscope Catalyst support Mineralogy chemistry.chemical_element 02 engineering and technology engineering.material 010402 general chemistry 01 natural sciences Materials Science(all) Specific surface area General Materials Science Magnesium Mechanical Engineering Spinel 021001 nanoscience & nanotechnology Condensed Matter Physics Microstructure 0104 chemical sciences Chemical engineering chemistry Mechanics of Materials Transmission electron microscopy engineering Crystallite 0210 nano-technology |
| Zdroj: | Materials Letters. 171:232-235 |
| ISSN: | 0167-577X |
| DOI: | 10.1016/j.matlet.2016.02.114 |
| Popis: | MgAl 2 O 4 is a stable catalyst support with potential for replacing gamma-alumina in several applications. However, synthesis of magnesium spinel requires elevated temperatures to avoid phase separation (in MgO and Al 2 O 3 ) at low temperatures, leading to coarsening and reduction of active surface area. In this work, nano CaO-doped and undoped magnesium aluminate were successfully prepared by Ultrasonic Spray Pyrolysis (USP), using a simple adapted experimental set-up operating at 1100 °C. During the process, the particles stay at high temperatures for a short period of time, allowing phase stability and limited coarsening. The influence of calcium oxide on the particles morphology and structure was investigated via X-ray diffraction, N 2 adsorption, X-ray fluorescence, scanning electron microscopy and transmission electron microscopy. The spinel nanopowders were obtained as spherical porous agglomerates of ~1 µm. The resulting powder showed low crystallite sizes in the 5–10 nm range and high specific surface area from 110.0 to 76.6 m 2 g −1 . |
| Databáze: | OpenAIRE |
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