Electrolyte perovskite-type

Franke and Winnick [105], using a K2S2O7 based electrolyte dispersed within the interstices of an inert K2Mg2(S04)3 matrix, were able to achieve removal efficiencies of SO2 greater than 99% at current efficiencies near 100%. A porous electrode constructed of a perovskite-type compound, Lao 8Sro.2Co03, was found to be conductive and stable in the corrosive cell environment. 

Schwarz et al. incorporated Perovskite-type electrocatalysts Al 8A o 2Cu04 (A = La, Pr. and Gd A = Sr and Th) in GDEs with the electrolyte solution 1 M KOH. They reported that CO2 was reduced to CH3OH, C2H5OH and w-CiHiOH with the total current yield of alcohols 40% of the current density 180 mA cnf They studied various perovskite type oxides, and argued that such oxides without Cu are not active for CO- reduction. 

Figure 9.5 Comparison of the oxygen ionic (a) and electronic (p- and n-type) (b) conductivity of selected solid electrolytes and mixed conductors under oxidizing conditions. The partial ionic conductivity of perovskite-type...

In this chapter, the distinctive features of proton conductors as an electrolyte for use in a fuel cell or in a steam electrolyser are discussed in comparison to those of oxide ion conductors. In addition, the possibility of using a proton conductor in a hydrogen gas separator is also described. As examples, the experiments on fuel-cells, steam electrolysers and hydrogen gas separators using proton conducting, perovskite-type oxides are described. 

Fig. 34.3. Performances of hydrogen fuel-cells using perovskite-type oxide ceramic as solid electrolyte and porous platinum electrodes, (a) SrCe03-based electrolyte (b) BaCe03-based electrolyte. 

In several cationic conductors, for example sodium-ion conductors based upon Na2S04 and perovskite-type lithium-ion conductors, rare-earth elements are important constituents, which directly or indirectly aid the ionic conduction in such solids. Somewhat unexpectedly, rare-earth elements in oxidation state (III), despite their large size and high charge, themselves may be the mobile component in solid electrolytes such as P-alumina, LaNb309 and Sc2(W04)3 oxides. 

Iwahara, H., Uchida, H., and Morimoto, K. (1990). High temperature solid electrolyte fuel cells using perovskite type based on BaCeOs. J Electrochem. Soc. 137 462-465. 

Solid electrolytes. These correspond to soHd materials in which the ionic mobility is insured by various intrinsic and extrinsic defects and are called solid ion conductors. Common examples are ion-conducting solids with rock salt or halite-type solids with a Bl structure (e.g., a-AgI), oxygen-conducting solids with a fluorite-type Cl structure (A"02), for instance CaF and yttria-stabilized zirconia (YSZ, ZrO with 8 mol.% Y O,), a pyro-chlore structure (A BjO ), perovskite-type oxides (A"B" 03), La Mo O, or solids with the spinel-type structure such as beta-aluminas (NaAl 0 ) for which the ionic conduction is ensured by Na mobility. 

Santhosh P, Manesh KM, Gopalan A, Lee K-P (2007) Novel amperometric carbon monoxide sensor based on multi-wedl carbon nanotubes grafted with polydiphenylamine-fabrication and performance. Sens Actuators B 125 92-99 Shai K, Wagner J (1982) Enhanced ionic conduction in dispersed solid electrolyte systems (DSES) and/or multiphase systems Agl-Al Oj, Agl-SiO, Agl-Ely ash, and Agl-AgBr. J Sohd State Chem 42 107-119 Shimizu Y, Yamashita N (2000) Solid electrolyte CO sensor using NASICON and perovskite-type oxide electrode. Sens Actuators B 64 102-106... 

SOFC cathodes are typically perovskite-type oxides formed as a composite with a suitable electrolyte (either YSZ for high-temperature operation or CGO for lower operating temperatures) and... 

Perovskite Based Electrolytes In mixed oxides of the perovskite-type oxide, general fomiula ABO3, ion vacancies can be generated by substimtion of both A and B catkms in valence stable oxides. 

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