Y-doped ceria

Ceria affords a number of important applications, such as catalysts in redox reactions (Kaspar et al., 1999, 2000 Trovarelli, 2002), electrode and electrolyte materials in fuel cells, optical films, polishing materials, and gas sensors. In order to improve the performance and/or stability of ceria materials, the doped materials, solid solutions and composites based on ceria are fabricated. For example, the ceria-zirconia solid solution is used in the three way catalyst, rare earth (such as Sm, Gd, or Y) doped ceria is used in solid state fuel cells, and ceria-noble metal or ceria-metal oxide composite catalysts are used for water-gas-shift (WGS) reaction and selective CO oxidation. 

Zhang, T.S. et al.. Effects of dopant concentration and aging on the electrical properties of Y-doped ceria electrolytes. Solid State Science 5 (2003) 1505-1511. 

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]. 

Nguyen TL, Kobayashi K, Honda T, Iimura Y, Kato K, Neghisi, A et al. Preparation and evaluation of doped ceria interlayer on supported stabilized zirconia electrolyte SOFCs by wet ceramic processes. Solid State Ionics 2004 174 163-174. 

Refs. [i] http /lwww.seca.doe.gov [ii] http //www.spice.or.jp/ fisher/ sofc.html descript [iii] http //www.pg.siemens.com/en/fuelcells/sofc/ tubular/index.cfm [iv] Weissbart J, Ruka R (1962) J Electrochem Soc 109 723 [v] Park S, Vohs JM, Gorte RJ (2000) Nature 404 265 [vi] Liou J, Liou P, Sheu T (1999) Physical properties and crystal chemistry of bismuth oxide solid solution. In Processing and characterization of electrochemical materials and devices. Proc Symp Ceram Trans 109, Indianapolis, pp 3-10 [vii] Singhal SC (2000) MRS Bull 25 16 [viii] Matsuzaki Y, Yasuda I (2001) J Electrochem Soc 148 A126 [ix] Ralph JM, Kilner JA, Steele BCH (1999) Improving Gd-doped ceria electrolytes for low temperature solid oxide fuel cells. In New Materials for batteries and fuel cells. Proc Symp San Francisco, pp 309-314... 

Eguchi, K., Akasaka, N., Mitsuyasu, H., and Nonaka, Y., Process of solid state reaction between doped ceria and zirconia, Solid State Ionics, 2000, 135, 589-594. 

Zhou, X.D., Scarfino, B., and Anderson, H.U., Electrical conductivity and stability of Gd-doped ceria/Y-doped zirconia ceramics and thin films. Solid State Ionics, 2004, 175 19-22. 

Figure 2.16. Left oxygen diffusion data of various ceria-coniaining materials 1 CeOj. single crystal 2 CeOj poly crystalline sample 3 CeogYojOiv 4 CCo Yo Oig 5 CeO,g 6 Ceo9Cao,0,/ 7 (0.3%)Od doped CcOj 8 Ce02. shaded area corresponds to oxygen diffusion values calculated from ionic conductivity of rare-earth doped ceria CC. M 02.o,. with x 0.2 and 0.3 using Eq. 2.29. Right details of oxygen diffusion coefficients of rare-earth doped ceria with x=0,3 from top to the bottom (M=Eu,Nd.Ho,Gd.Er.Sm,Y.La.Yb,Dy).

Oxygen migration in doped cerias has been recently studied with molecular dynamics methods by Inaba et al and Hayashi et These authors examined the systems (Ce02)i (A 203) /2 (where M = Y Gd La) with dopant contents in the range 0 — 15% mol. The diffusion coefficient of oxygen at 1273 K was evaluated from the simulations at different compositions with a maximum at around 10% mol of dopant. 

Huang, T.-J. and Jhao, S.-Y. Ni-Cu/samaria-doped ceria catalysts for steam reforming of methane in the presence of carbon dioxide. Applied Catalysis. A, General, 2006, 302 (2), 325. 

Wang, B.H., Wang, J.D., Liu, R., Yie, Y.H., and Li, Z.J. 2007. Synthesis of ammonia from natural gas at atmospheric pressure with doped ceria -Ca/PO lj-KjPO composite electrolyte and its proton conductivity at intermediate temperature. Journal of Solid State Electrochemistry 11, 27-31. 

Xia C, Li Y, Tian Y, Liu Q, Wang Z, Jia L, Zhao Y and Li Y (2010), Intermediate temperature fuel cell with a doped ceria-carbonate composite electrolyte , / Power Sources, 195,3149-3154. 

Liu Y, He T, Wang J, Shu W (2005) The effect of Pr co-dopant on the performance of sohd oxide fuel cells with Sm-doped ceria electrolyte. J AUoy Compd 389 317-322... 

Sameshima S, Hirata Y, Ehira Y (2006) Structural chtmge in Sm- and Nd-doped ceria under a low oxygen partied pressure. J Alloys Compd 408-412 628-631... 

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). 

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. 

Norton, T.T., Lu, B., and Lin, Y.S. (2014) Carbon dioxide permeation properties and stability of samarium-doped-ceria carbonate dual-phase membranes. /. Membr. Sci., 467,... 

Xu, X.Y, Jiang, Z.Y, Fan, X. Xia, C.R. LSM-SDC electrodes fabricated with an ion-impregnating process for SOFCs with doped ceria electrolytes. Solid State Ionics 111 (2006), pp. 2113-2117. 

Gd-doped ceria mixed with Zr and Y, and various Ti02-based systems. In such anodes, there is mixed conductivity for both electrons and oxygen ions. A further advantage of using mixed conductors as anodes is that they can provide a means of extending the three-phase boundary between reactant-anode electrolyte, as shown in Figure 7.24. 

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