Influence of organic solvent on solvothermal synthesis of samaria and gadolinia doped ceria – nickel oxide composites Alexander Rodrigo Arakaki 1,a , Sandra Maria Cunha 1,b , Walter Kenji Yoshito 1,c , Valter Ussui 1,d , Dolores Ribeiro Ricci Lazar 1,e 1 Instituto de Pesquisas Energéticas e Nucleares – Av. Prof. Lineu Prestes, 2242 Cidade Universitária, SP, SP, Brasil a alexander@ipen.br, b smcunha@ipen.br, c wyoshito@ipen.br, d vussui@ipen.br, e drlazar@ipen.br Keywords: Doped-ceria / nickel oxide, synthesis, coprecipitation, solvothermal treatment Abstract. The synthesis and ceramic processing of samaria and gadolinia doped ceria - nickel oxide composites, mainly applied as Solid Oxide Fuel Cell anodes, were studied in this work. Powders with composition Ce 0.8 (SmGd) 0.2 O 1,9 /NiO and mass ratio of 40/60%, were synthesized by hydroxide coprecipitation with CTAB surfactant, followed by solvothermal treatment in n-butanol, ethanol and n-propanol at 150 ºC for 16 hours, calcination at 600 o C for 1 hour and milling. Sintering of compacted samples was performed at 1300 o C for 1 hour. The powders were analyzed by X-ray diffraction, scanning electron microscopy, nitrogen adsorption method (BET), laser beam scattering (Cilas) and TG/DTA. The ceramics were analyzed by scanning electron microscopy, EDS, XRD and density measurements by Archimedes method. The results showed that the powders have a high specific surface area (42 - 85 m 2 /g). The ceramic characterizations showed a high chemical homogeneity and density value of 99% TD for powders treated with ethanol and propanol. Introduction The (CeO 2 ) based ceramics have been widely studied due to its high ionic conductivity allowing their use as Solid Oxide Fuel Cell electrolyte. The dopants that provide highest improvement in the ionic conductivity are the trivalents rare earths samaria and gadolinia. The anodic materials that present high chemical, physical compatibility and highest electronic conductivity with ceria based electrolytes are the cermets compounds containing metallic nickel and the same electrolyte material [1,2]. Metallic nickel can be formed by reduction in hydrogen atmosphere from the nickel oxide produced by coprecipitation with the gadolinia and samaria doped ceria (GSDC) [3]. The anodic composite performance depends on the powder characteristics such as particle size, surface area, and chemical homogeneity, as well as on ceramic microstructure, including triple phase boundaries (TPB) and percolation chains [1-3]. It is well known that these properties can be adjusted during the powder synthesis and gel precipitation is a usual employed method. The association with solvothermal technique was recently introduced to allow the preparation of crystalline nanopowders at low temperatures [4]. This process involves the use of an organic solvent in an autoclave under autogenous pressure of 10-30 atm generated by temperatures from 100 to 250ºC. These conditions promote the growth of the particles in preferred directions, making possible the formation of particulate forms of nanocubes, nanorods, nanotubes and nanoplates[5]. The shape of the particles can also be changed with the employment of a surfactant in precipitation, which operates in the nucleation, particle growth, coagulation and flocculation[6]. For this purpose parameters like pH of precursors solution, reaction temperature and time, solute concentration and type of solvent have to be controlled[5,6]. In this work samaria and gadolinia doped ceria - nickel oxide powders have been synthesized by coprecipitation, in the presence of CTAB (hexadecyltrimethylammonium bromide) surfactant, followed by solvothermal treatment. Eighth International Latin American Conference on Powder Technology, November 06 to 09, Costão do Santinho, Florianópolis, SC, Brazil 1834