PREPARATION of Gd2O3 NANOMATERIALS via SOLUTION COMBUSTION SYNTHESIS FOR OXIDATIVE COUPLING OF METHANE

Abstract

In this study, in the production of Gd₂O₃ material which has many usage areas, solution combustion synthesis was used and the changes in the physical and structural properties of the material were investigated by changing the oxidant/fuel ratio. The resulting metal oxide powders were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area, Thermogravimetric-Differential thermal analysis (TG-DTA) and scanning electron microscopy (SEM) analysis and tested in oxidative coupling of methane. Cubic and monoclinic phases were observed in Gd₂O₃ crystal structure at fuel-rich and stoichiometric conditions, and only cubic phase was determined at fuel-lean conditions. It was determined that the obtained powders were mesoporous and the highest BET surface area was obtained at stoichiometric oxidant/fuel ratio (18.6 m²/g). It was determined that the powders were formed from rather small particles (<30 nm) and with layered or stacked structure. The catalytic performance of Gd₂O₃ nanoparticles was found to be dependent on the BET surface area and crystal structure. The highest C₂ yield was obtained at 720°C with Gd₂O₃-0.5 (8.5%).

Keywords

• Gd2O3,solution combustion synthesis,oxidative coupling of methane

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