[en] Full text: Cerium is an important rare earth metal with a good conducting nature and used for a good range of applications. When it comes to use his oxide form in nanoscale, the properties and the uses are even wider. Lately, Cerium Oxide nanoparticles have been attracting some attention because of its use as heterogeneous catalyst/catalyst oxide support, sensor, electrochemical solar cell and its incredible properties such as high thermal stability, electrical conductivity, high oxygen mobility and storage capacity. In this work, Silver doped CeO₂ nanostructures were synthesized by the hydrothermal method. In order to study the nanostructure’s format effect on its catalytic potential, different types and concentrations of reducing agent were used, obtaining morphologically different nanostructures. To test their catalytic activity, a benzyl alcohol oxidation reaction was realized on the presence of the silver doped Cerium Oxide nanostructures. All nanostructures were characterized by x-ray diffraction (XRD), RAMAN spectroscopy, UV-visible spectroscopy, infrared spectroscopy (FT-IR) and scanning electron microscope (SEM). The catalytic activity was investigated in the benzyl alcohol oxidation reaction and followed by infrared spectroscopy, UV-visible spectroscopy and gas chromatography coupled to mass spectrometer (GC-MS). X-ray diffraction results indicated that the nanostructures have a cubic structure (JCPDS # 34-0394), with crystals of varied size according to their morphology. The catalyst performance was verified by the conversion of the substrate of the oxidation reaction into its derivatives and shown by the chromatogram, the mass spectrum and the UV spectrum. The results showed that the morphology of the nanoparticle is an important factor in the catalytic activity, which was evidenced by the variation of the conversion rate caused by the change in the nanostructure. The microscopy images showed the plates, cubes and whiskers formats of CeO₂ nanostructures. (author)