Influence of humidity on a potentiometric CO{sub 2} gas sensor using a combined electrolyte of sodium ion conducting glass and stabilized zirconia

Journal Article · Tue Sep 01 04:00:00 EDT 1998 · Journal of the Electrochemical Society

DOI:https://doi.org/10.1149/1.1838751· OSTI ID:659111

Aono, Hiromichi; Supriyatno, Heru; Sadaoka, Yoshihiko ^[1]

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1. Ehime Univ., Matsuyama (Japan). Dept. of Materials Science and Engineering

A CO{sub 2} gas sensor using a combined solid electrolyte of a Na{sup +} conducting Na{sub 2}O-Al{sub 2}O{sub 3}-4SiO{sub 2} glass and an yttria-stabilized zirconia was prepared, and its sensing properties in dry and wet gases were investigated using a variable flow rate of the test gases. The glassy electrolyte in the sensor was suitable as a CO{sub 2} sensing material because of its high density and good contact between the electrolytes. In a dry atmosphere, excellent results were obtained for the CO{sub 2} gas concentration dependence of the electromotive force (EMF), expressed by EMF (mV) = 547.5 {minus} 74.0 log [C{sub co{sub 2}}/ppm] at 470 C in which the sensitivity of 74.0 mV/decade was in fair agreement with the theoretical value based on a two-electron electrochemical reaction. In the case of wet CO{sub 2} gas, the sensitivities and response time were depressed even for a high CO{sub 2} gas concentration. The decomposition of Na{sub 2}CO{sub 3} into sodium oxide on the Pt electrode was accelerated in the presence of H{sub 2}O. The reason for the depression of the sensing properties in a humid condition could be ascribed to its reformation reaction as a side reaction.

• Sponsoring Organization: USDOE
• OSTI ID: 659111
• Journal Information: Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 9 Vol. 145; ISSN JESOAN; ISSN 0013-4651
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
AIR POLLUTION MONITORS
CARBON DIOXIDE
HUMIDITY
PERFORMANCE
POTENTIOMETRY
SOLID ELECTROLYTES