The Control of Oxygen Activities in Argon-Oxygen Mixtures by Coulometric Titration

Agrawal, Yogesh K.; Short, David W.; Gruenke, Roger; Rapp, Robert A.

doi:10.1149/1.2401815

Cited by 45 publications

(15 citation statements)

References 5 publications

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“…[10], [11], and [14] it is found that According to Eq. [16] at Po2 < Po2 'nin" (i.e., Cads << 1) mass transport limitation of oxygen atoms occurs at the cathode and according to Eq. [1'7] at Po2 > Po2 rain" (i.e., eads ~ 1) mass transport hmitation of oxygen atoms occurs at the anode.…”

Section: Resultsmentioning

confidence: 99%

“…Measurements were performed in the temperature range 770-1050 K and with N2-O2 mixtures in the oxygen partial pressure range of 10-5-1 atm O2. The oxygen partial pressures in the range of 10-2-1 atm were obtained by mixing appropriate O2/N2 mixtures and in the range of 10-~-10-2 arm by an oxygen pump (15,16). The oxygen partial pressure is measured using an oxygen sensor based on stabilized zirconia.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Oxygen Transfer on Substituted ZrO2, Bi2 O 3, and CeO2 Electrolytes with Platinum Electrodes: I . Electrode Resistance by D‐C Polarization

Verkerk

Hammink

Burggraaf

1983

J. Electrochem. Soc.

163

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The electrode behavior of Ptosputtered and PT-gauze electrodes on ZrO2-Y203, Bi20~-Er20.~, and CeO~-Gd203 solid electrolytes was investigated by means of d-c measurements in the temperature region of 770-1050 K and in the oxygen partial pressure region of 10 -~ -1 atm O2 using N2-O2 mixtures. On these different materials the same electrode morphology was realized and was preserved during the subsequent experiments. The electrode process is strongly influenced by the nature of the electrolyte. The electrode resistance for Pt electrodes on Bi203-Er203 was found to be many times lower than on ZrO2-Y20~ and CeO2-Gd20~. On zirconia-and ceria-based materials-diffusion of atomic oxygen on the Pt electrode is the rate-determining step in the electrode process, whereas for bismuth sesquioxide-based materials diffusion on the oxide surfaces is rate determining.There is a considerable interest in solid electrolytes for use in oxygen sensors, oxygen pumps, and high temperature fuel cells. In these applications the electrode polarization and the electrolyte resistance both play an important role. These effects influence the response of an oxygen sensor and give rise to energy losses and therefore to a decreased efficiency, of oxygen pumps and fuel cells. Many studies are performed on electrode processes. However, the dominant elementary steps of the overall process are still unknown in most cases.The kinetics of the electrode process is strongly influenced by the electrode structure (1-6), electrode material (4, 5, 7-9), and the electrolyte (4, 5, 7). Information about the role of the electrolyte in the electrode process is very scarce and is limited to the role of the dopant. Schouler (4) found that the oxygen partial pressure dependence of the electrode resistance of a sputtered platinum electrode depends on the Y203 content of the ThO2 electrolyte. Fabry and Kleitz (7) found that the activation energy of the electrode resistance of a point electrode on calcia-stabilized zirconia is higher than that on yttria-stabilized zirconia. Wang anal Nowick (5) reported that the exchange current of a Pt-paste electrode is not influenced by the nature and the. concentration of the dopant of the CeO2 electrolyte.Even less attention is paid to the influence of the nature of the electrolyte on the overall electrode proi Present address:

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Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Oxygen Transfer on Substituted ZrO2, Bi2 O 3, and CeO2 Electrolytes with Platinum Electrodes: I . Electrode Resistance by D‐C Polarization

Verkerk

Hammink

Burggraaf

1983

J. Electrochem. Soc.

163

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show abstract

“…The verification of Faraday's law has been previously obtained by Fouletier et al (6,10) in their tests of a solid-electrolyte oxygen pump. However, both Fouletier et al (10) and Agrawal et al (11) observed inaccuracies when an electrode was common to both pump and measuring cells in units which were used to simultaneously control and measure oxygen contents in a flowing carrier gas. Therefore, the four-electrode two-cell approach shown in Figure 1 was selected rather than a possible three-electrode arrangement.…”

Section: Resultsmentioning

confidence: 99%

Internal-reference solid-electrolyte oxygen sensor

Haaland¹

1977

Anal. Chem.

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“…Yuan and Kr6ger [1] used a three-electrode assembly with a common inner electrode. Agrawal et al [2] and Fouletier et al [3] used a four-electrode assembly in a common furnace. In our laboratory, both the pump and the sensor were set up in two independent furnaces to avoid the electrical interface between them.…”

Section: Methodsmentioning

confidence: 99%