Gadolinia-doped ceria

TABLE 1.3 Ionic Conductivity Data for Selected Gadolinia-Doped Ceria (GDC)... 

FIGURE 1.34 Comparison in open-circuit voltage of a unit cell with gadolinia-doped ceria electrolyte containing 3 mol% of Ln(Y, Sm, Nd, Pr, and La) codopant [134]. 

Various strategies have been developed to improve the electrocatalytic activities of the LSM-based cathodes. Murray and Barnett [68, 69] showed that the addition of YSZ and gadolinia-doped ceria (GDC) phase to LSM significantly reduced the electrode polarization resistance. Figure 3.7 shows the electrode polarization resistance of the LSM/GDC tested in the air [69], The electrode polarization resistance... 

A significant step forward in our understanding of Pt was taken by Verkerk and Burgraff, who in 1983 analyzed the impedance of porous sputtered Pt (and Pt gauze) electrodes on YSZ and gadolinia-doped ceria (GDC). As shown in Figure 11, they used a Randles circuit to model the interfacial contributions to the impedance, allowing them to subtract from the data the contributions of uncompensated iR and... 

Table 15.1. Expansion on reduction of pure and gadolinia doped ceria ai lOOtTC. Sv.(>o Vegard s...

Yttria-doped zirconia and gadolinia-doped ceria oxygen ion conductors and strontium yttrium zirconium oxide proton conductors are being investigated as the solid electrolyte. 

The present work was focused on the synthesis of nanocrystalline components for electrochemical cells via the cellulose-precursor technique. This method was used to prepare nanostructured intermediate-temperature (IT) SOFC anodes made of a series of cermets comprising gadolinia-doped ceria (CGO), yttria-stabilized zirconia (YSZ), Gdi.86Cao.i4Ti207.5 (GCTO) pyrochlore, metallic nickel and copper. Perovskite-type SrFcojAlo.sOs.s (SFA) powder, also obtained via the cellulose precursor, was applied onto membranes of the same composition to enhance specific surface area and electrocatalytic activity in the reactors for methane conversion [3]. 

Trunec has described the thermoplastic extrusion of thin-wall tubes made of yttria-stabilized zirconia and gadolinia-doped ceria [Tru 04], These ceramics are used for solid oxide electrolyte applications, e.g. solid oxide fuel cells. The thermoplastic binder system used consists of ethylene-vinyl acetate copolymer, parafHn wax and stearic acid. With this system tubes with an outer diameter of 10.5 mm and wall thicknesses of 290 and 280 pm could be fabricated. 

Marina AO, Mogensen M (1999) High-temperature conversion of methane on a composite gadolinia-doped ceria-gold electrode. Appl Catal A 189 117-126... 

Best known examples of oxides with pure ionic conductivity are yttria-stabilized zirconia (YSZ), gadolinia-doped ceria (CGO) with fluorite structure, and strontia-doped lanthanum gal-lates (LSG) with perovskite structure. These oxides exhibit high thermodynamic stability because of the absence of transition-metal ions. These ionic conductors differ in their high oxide-ionic conductivity as follows LSG > CGO > YSZ. They show low electronic conductivity and low catalytic activity. For their utilization as oxygen membrane materials, an electronic part of conductivity is required. 

Ruiz-Trejo E, Sirman JD, Baikov Ju M, Kilner JA (1998) Oxygen ion diffusivity, surface exchange and ionic conductivity in single crystal Gadolinia doped Ceria. Solid State Ion 113-115 565-569... 

The performance of SC-SOFCs could be further improved by the simultaneous addition of 25 wt% gadolinia-doped ceria (GDC) and 15 wt% Mn02, respectively, to the anode and cathode [5]. The resulting fuel cell generated an OCV of 833 mV and a peak power density of 162 mW cm in a methane-air mixture feed at 950 °C. They explained that the improved performance was due to high electro-catalytic activity of each electrode for the corresponding target reaction. 

Rupp JLM Infortuna A, Gauckler LJ. Thermodynamic stability of gadolinia-doped ceria thin film electrolytes for micro-solid oxide fuel cells. Journal of the American Ceramic Society 90(6) 1792—1797... 

W.X. Kao, M.C, Lee, T.N. Lin, C.H. Wang, and Y.C. Chang, Fabrication and Characterization of a Bao5Sro5Coo.8Feo203. -gadolinia-doped Ceria Cathode for an Anode-supported Solid-oxide Fuel Cell, J. Power Sources, 195, 2220-2223 (2010). 

Aravind, P.V., J.P. Ouweltjes, and J. Schoonman, Diffusion Impedance on Nickel/Gadolinia-Doped Ceria Anodes for Solid Oxide Fuel Cells. Journal of The Electrochemical Society, 2009. 156(12) P.B1417-B1422. 

Chen, C.H., Varhaug, K.N., Schonman, J. Coatings yttria-stabilized-zirconia (YSZ) thin films on gadolinia-doped ceria (GCO) by the electrostatic spray deposition (BSD) technique. J. Mater. Synth. Process. 4, 189-194 (1996)... 

Aravind PV, Ouweltjes JP, Woudstra N, Rietveld G (2008) Impact of biomass-derived contaminants on SOFCs with Ni/Gadolinia-doped ceria anodes. Electrochem Solid State Lett 11(2) B24-B28... 

Azad S, Marina OA, Wang CM, Saraf L, Shutthanandan V, McCready DE, El-Azab A, Jaffe JE, Engelhard MH, Peden CFIF, Thevuthasan S (2005) Nanoscale effects on ion conductance of layer-by-layer structures of gadolinia-doped ceria and zirconia. Appl Phys Lett 86(13) 131906... 

Huang, H., Giir, T.M., Saito, Y., and Prinz, F. (2006) High ionic conductivity in ultrathin nanocrystalline gadolinia-doped ceria films. Appl. Phys. Lett., 89, 143107-143709. 

Liu, Q.L., Khor, KA., Chan, SXI., and Chen, X.J. (2006) Anode-supported solid oxide fuel cell with yttria-stabilized zirconia/gadolinia-doped ceria bilayer electrolyte prepared by wet ceramic cosintering process. J. Power Sources,... 

Waller, D., Lane, JA., Kilner, JA., and Steele, B.C.H. (1996) The effect of thermal treatment on the resistance of LSCF electrodes on gadolinia doped ceria electrolytes. Solid State Ionics, 86-88, 161-7T2. 

Muecke, UP, Graf, S., Rhyner, U. Gauckler, L.J. Microstructure and electrical conductivity of nanocrystalline nickeland nickel oxide/gadolinia-doped ceria thin films. Acta Mater. 56 (2008), pp. 677-687. 

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