Zirconia membrane electrode

The reactions between cerium trichloride and oxide ions were initially studied in the pure KCl-NaCl equimolar mixture at 1000 K by the method of potentiometric titration using a calcium-stabilized zirconia membrane electrode. The titration curves clearly demonstrated the existence of the soluble cerium oxychloride CeO+ and precipitated cerium oxide ... 

In 1963, an important development was the zirconia membrane electrode showing ionic conductivity due to oxide ion (10). This electrode, initially composed of calcium oxide and zirconia, later has appeared in other forms, notably zirconia-yttria and zirconia-thoria. It has proven effective for oxide ion activity measurements over an extremely wide range at temperature of 1000 or higher, but it is of limited use at temperatures below 500 because of excessive resistance. 

FIGURE 5.13 Reference electrode response in a zirconia membrane cell over five thermal cycles. 

Badwal, S.P.S. and Ciacchi, E.T., Performance of zirconia membrane oxygen sensors at low temperatures with nonstoichiometric oxide electrodes, J. Appl. Electrochem. 16 (1986) 28-40. 

Figure 26-S presents a construction which is fairly insensitive to thermal shock [22]. A zirconia membrane is tightly sintered to a Pt tube which forms the electrode shaft. The lifetime also of this arrangement is limited by corrosion of the membrane, which, in addition, is subject to so-called bubble boring, especially in a horizontal position [4].

With data on the activity of hydrogen ion in the standard solution available from model estimations, relatiorrships between the pH and cell potential, and hence a practical pH scale, for supercritical systems was developed. The potential of the cell comprising a pH sensor (yttria stabilized zirconia membrane) and a reference electrode (silver/silver chloride external pressure balanced electrode) (Emeas) can be written in the following form "... 

The issue of mismatch of thermal expansion coefficients similar to that for a composite membrane is also very critical for fuel cells. In the fuel cells, electrodes are attached to solid electrolyte membranes. Significant temperature variations during applications, pretreatments or regeneration of the membranes (e.g., decoking) can cause serious mechanical problems associated with incompatible thermal expansions of different components. A possible partial solution to the above problem is to use partially stabilized instead of fully stabilized zirconia. The former has a significantly lower thermal expansion coefficient than the latter. 

This experimental run was the fifth run using coal gas. It used two tapes of MgO and one mat of zirconia doth as the membrane matrix material. The electrodes were both lithiated NiO. The acrylic binders were burned out under an 0, atmosphere and the li/K eutectic-composition electrolyte was added with the cell at run temperature. The inlet gases were passed throu a stainless steel... 

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