SYNTHESIS AND MIXED CONDUCTIVITY OF Ce_1-x-yLa_xPr_yO_2-δ FOR CATALYTICALLY ACTIVE INTERLAYERS OF SOLID OXIDE FUEL CELLS

Developments of high-efficiency solid oxide fuel cells (SOFCs) make it necessary to create multilayered electrode systems providing both a superior electrochemical activity and stability in the entire range of SOFC operation conditions. This work summarizes experimental results on the functional properties of fluorite-like Ce_1-x-yLa_xPr_yO_2-δ (x=0.29-40, y=0.10-0.14) mixed conductors, which were synthesized by the glycine-nitrate technique and studied as potential materials of the catalytically active protective interlayers for the SOFC electrodes. Using the data on total conductivity as a function of the oxygen partial pressure varied from 0.35 atm down to 10^-19 atm 973-1223 К, the defect formation and transport processes were modelled. Increasing praseodymium concentration was found to increase p-type electronic conduction under oxidizing conditions, whilst the dominant defect reaction at low oxygen chemical potentials is the reduction of cerium cations, leading to the formation of n-type electronic charge carriers. The chemical reactivity with lanthanum gallate-based solid electrolyte (LSGM) was assessed employing annealing of the powder mixtures and X-ray diffraction analysis. Model cells with perovskite-like PrBaFe_1.2Ni_0.8O_5+δ electrodes and multifunctional Ce_0.50La_0.40Pr_0.10O_2-δ sublayers in contact with the lanthanum gallate solid-electrolyte membranes were evaluated by scanning electron microscopy.

глицин-нитратный метод, твердооксидные топливные элементы (ТОТЭ), смешанные проводники на основе диоксида церия, многофункциональный подслой, равновесия дефектов, glycine-nitrate technique, solid oxide fuel cells (SOFC), ceria-based mixed conductors, multifunctional sublayer, defect equilibria

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