Synthesis and characterization of cerium oxide by electrochemical methods

Ceria-based materials have been synthesized by electrochemical process. Electrodeposition is an interesting cheap method which can be performed at ambient pressure and rather low temperature (less than 100 degrees C). Moreover, it is easy to control in situ the film thickness. Ceria coatings were obtained by an indirect electrodeposition method. A potentio-static technique (-0.7 V/SCE) was used to first reduce a hydroxide precursor (O-2 or NO3-) before leading to the formation of cerium oxide after 2h of deposition time. This work focused on the characterization of ceria films deposited onto stainless steel in view of high temperature fuel cell applications. The chosen deposition conditions lead to quite adherent, homogenous and covering films. The microstructure and the crystallinity of the ceria thin layers were characterized by SEM, TEM and XRD measurements. Electrochemical microscopy (SECM) was also used to locally study the conductive properties of ceria layers and the homogeneity of the deposited films. Finally, electrochemical characterizations such as impedance spectroscopy were performed under air atmosphere. (c) 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim