The model RhO_x/CeO₂ systems were prepared by radio‐frequency (RF) plasma sputtering of Rh electrode in O₂ or Ar/O₂ atmosphere. Thermal stability of the systems and their reaction probability towards CO oxidation were studied by X‐ray photoelectron spectroscopy. It was shown that the small oxidized Rh nanoparticles on the CeO₂ surface (RhO_x/CeO₂) obtained by RF sputtering in O₂ have spectroscopic characteristics close to those of Rh³⁺ ions highly dispersed in ceria lattice. The RhO_x/CeO₂ system remains stable upon heating in vacuum at 450°C and shows reactivity towards CO oxidation at T > 200°C. RF sputtering in Ar/O₂ atmosphere results in the formation of larger rhodium nanoparticles that are close to Rh₂O₃ oxide. The Rh₂O₃/CeO₂ system demonstrates lower activity in CO oxidation and cannot be reduced at a temperature below 300°C.

中文翻译：

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射频等离子体溅射制备的RhOx / CeO2纳米复合材料的活性和热稳定性

RhO _x / CeO ₂模型系统是通过在O ₂或Ar / O ₂气氛中对Rh电极进行射频（RF）等离子体溅射制备的。通过X射线光电子能谱研究了系统的热稳定性及其对CO氧化的反应可能性。结果表明，在O _2中通过RF溅射获得的CeO ₂表面上的小氧化Rh纳米粒子（RhO _x / CeO ₂）具有与高度分散在二氧化铈晶格中的Rh ³⁺离子接近的光谱特性。RhO _x / CeO ₂在真空中于450°C加热时，系统保持稳定，并在T > 200°C下表现出对CO氧化的反应性。在Ar / O ₂气氛中进行RF溅射会形成较大的铑纳米颗粒，其接近Rh ₂ O ₃氧化物。Rh ₂ O ₃ / CeO ₂系统显示出较低的CO氧化活性，并且在低于300°C的温度下无法还原。