Zirconia solid electrolytes

S. Seimanides, P. Tsiakaras, X.E. Verykios, and C.G. Vayenas, Oxidative Coupling of Methane over Yttria-doped Zirconia Solid Electrolyte, Appl. Catal. 68, 41-53 (1991). 

Zirconia solid electrolyte and zinc oxide sensing electrodes were used as a high-temperature NOx sensor [470, 471]. The response of the electrode potential was linear for the logarithm of NOx (NO) concentration from 40 to 450 ppm. 

Arranged in layered fashion on the alumina substrate are the zirconia underlayer, the platinum reference electrode, the zirconia solid electrolyte stabilized with 5.1 mole % Y2O3, the platinum measurement electrode, and finally,the protective spinel (A203 Mg0) layer. The zirconia layer is Umm long, 1+mm wide and 30pm thick. 

The heater, the underlayer, the zirconia solid electrolyte and the two electrodes are formed by screen printing and sintering. The sintering condition is at 1,U80°C for 2HR in air. The temperature of sensor surface rises to 600°C with plasma spraying. 

As a result, the zirconia solid electrolyte, two electrodes and protective spinel layer become porous. 

Figure 23 The oxygen concentration cell with calcinm-stabilized zirconia solid electrolyte. (Ref. 42. Reproduced by permission of John Wiley Sons, Inc.)...

Clark D.J., Losey R.W. and Suitor J.W., Separation of oxygen by using zirconia solid electrolyte membranes. Gas Separation and Purification 6 201 (1992). 

J.W. Suitor, D.J. Clark and R.W. Losey, Development of alternative oxygen production source using a zirconia solid electrolyte membrane, in Technical progress report for fiscal years 1987,1988 and 1990. Jet Propulsion Laboratory Internal Document D7790,1990. T.J. Mazanec, T.L. Cable and J.G. Frye, Jr., Electrocatalytic cells for chemical reaction. Solid State Ionics, 53-56 (1992) 111-118. 

Figure 15. Polarization curves (IR-free) for hydrogen oxidation at Pt anodes attached to various zirconia solid electrolytes measured in humidified hydrogen ( [H2O] = 0.04 atm). Zirconia electrolyte 0 8Yb, O 8Y, A 4 Y, 3Y. Reprinted from Ref. 44, Copyright (1995), American Chemical Society.

Figure 17. Dependencies of exchange current density jo at various electrodes on the ionic conductivity of various zirconia solid electrolytes (A) SDC (dashed, dash-dotted, and dotted lines) and Ru (0.5 mg/cm )-dispersed SDC anodes in humidified Hi. Reprinted from Ref. 45, Copyright (1997), with permission from The Electrochemical Society, (B) Pt cathodes in Oj, (C) LfCi jsSriu MnO, (LSM, dashed lines) and Pt (0.1 nig/cnr(-dispersed LSM cathodes in Oi. Each jo value was calculated from the polarization resistance (Rp, 2 tm ), since linear relationships were observed between 7 and j for rj < 0.1 V at all the electrodes and 7 ccii between 800 and 1000°C jo = (RT/nF)Rp. Reproduced by Ref. 46, Copyright (1999), by permission from The Electrochemical Society. 

E.M.F. method using zirconia solid electrolyte. ISIJ Int., 35 (5), 512-18. 

Imanaka, N., Kamikawa. M.. Tamura. S. and Adachi, G. (1999) CO2 sensor based on the combination of trivalent Sc ion-conducting Sc2(WO4) and O ion-conducting stabilized zirconia solid electrolytes. Electrochem. Solid-State Lett., 2 (11), 602-4. 

Miura, N., Nakatou, M. and Zhuiykoy S. (2003) Impedancemetric gas sensorbased on zirconia solid electrolyte and oxide sensing electrode for detecting total NOx at high temperature. Sens. Actuators B, 93 (1-3), 221-8. 

ELECTROCHEMISTRY OF ZIRCONIA SOLID ELECTROLYTES AS THE BASIS FOR UNDERSTANDING ELECTROCHEMICAL GAS SENSORS... 

Zhou, M. and Ahmad, A., Synthesis, processing and characterization of calcia-stabi-hzed zirconia solid electrolytes for oxygen sensing applications. Materials Research Bulletin 41 (2006) 690-696. 

FIGURE 3.17 Complex impedance plots in base air and the sample gas with each of the various concentrations of (a) NO and(b) NO2 at 700°C for the YSZ-based sensor attached with a ZnCr204-SE. (Reprinted from Miura, N., Nakaton M., and Zhuiykov, S., Impedanee-metric gas sensor based on zirconia solid electrolyte and oxide sensing electrode for detecting total NOj at high temperature, Sens. Actuators B, Chem. 93 (2003) 221-228, with permission from Elsevier Science.)... 

Zhuiykov, S. et al.. High-temperature NO sensors using zirconia solid electrolyte and zinc-family oxide sensing electrode. Solid State Ionics 152-153 (2002) 801-807. 

The flrst commercial equipment with zirconia solid-electrolyte cells, which has been produced in the Westinghouse Scientiflc Equipment Department in Pittsburgh since 1962, served only as an oxygen gauge. Measurements of the oxygen concentration in breathing gas (Figure 25-15) illustrated the fast response of the sensor. The achieved speed of response is the one that is connected with the gas transfer, and not the one of the sensor itself [66]. 

Figure 26-7. Experimental arrangement for measuring thermoelectric emfs of zirconia solid electrolytes.

Various authors have reported different temperatures of eutectoid decomposition, ranging from 1000 to 1140 °C [183-185]. The eutectoid transformation is a rather slow process, and is therefore not seen in conventionally aged samples. However, a large cubic phase field also exists which, together vfith slow transformation, facilitates the existence of a fully cubic structure, providing the basis for calcia-stabilized zirconia solid electrolytes. 

Among the zirconia systems, yttria-stabilized zirconia is the most familiar oxygen-ion conductor, with widespread practical sqiplications in sensors (Seiyama 1988-94), oxygen pumps (Fouletier et al. 1975), fuel cells (Minn and Takahashi 1995), and steam electrolysers (Donitz and Erdle 1985). At a dopant concentration of around 8mol% of Y2O3, the zirconia solid electrolyte can achieve a conductivity value of 10 S/cm at 1273 K with an activation energy of 0.8 eV. 

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