engleski

Coarsening kinetics analysis of nanocrystalline copper doped ceria

Cerium (IV) oxide (CeO2) is used as a catalyst in many industrial processes, as well as in everyday life, i.e. for elimination of harmful components in car exhaust. The advantages of CeO2 over conventional catalysts are low cost, availability, better poisoning resistance and high catalytic activity due to the facile Ce4+ / Ce3+ redox reaction, high oxygen storage capacity and the stability of the fluorite crystal structure during oxygen storage and release. CeO2 nanoparticles have higher specific surface area and better redox properties, and thus an increased catalytic activity in comparison to bulk materials, but the problem occurs at elevated temperatures, since nanoparticles are very prone to aggregation and coarsening. In order to increase the thermal stability of CeO2 nanoparticles, but also improve its catalytic properties, metal ions are incorporated into the CeO2 crystal structure. In order to determine the effect of doping on thermal stability of CeO2, it is essential to perform a coarsening kinetics analysis. The aim of this study was to investigate the coarsening kinetics of nanocrystalline CeO2 and CeO2 doped with 10 mol. % of copper. Samples were prepared by hydrothermal synthesis, characterized, and thermally treated at different temperatures and processing times. The as- prepared and thermally treated samples were analyzed by X-ray diffraction analysis and the crystallite sizes were calculated using the Scherrer equation. Based on the obtained crystallite sizes, kinetic parameters were determined and it was found that copper addition has a positive effect on the thermal stability of CeO2.

cerium (IV) oxide ; coarsening kinetics ; hydrothermal synthesis ; doping

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