Physical principles governing nonideal behavior of the zirconia oxygen sensor

Journal Article · Sat Jan 01 04:00:00 EST 1977 · J. Electrochem. Soc.; (United States)

DOI:https://doi.org/10.1149/1.2133235· OSTI ID:7227036

Fleming, W J

Zirconia galvanic cells of the form exhaust gas, Pt parallel stabilized ZrO/sub 2/ parallel Pt, air are installed in the exhaust pipe of automobile engines to provide a voltage signal indicative of engine air-fuel ratio. To account for deviation of experimental sensor behavior from predicted ideal performance, a physical model of nonideal sensors is derived. Nonideal behavior is accounted for by simultaneous presence of two electrochemical reactions occurring at the anode (exhaust gas) electrode; one reaction involves oxygen and the other involves carbon monoxide. Correlation of calculated sensor characteristics with experimental results shows that nonideal sensor electrodes possess surface adsorption properties and catalytic activities which are many orders of magnitude less than ideal equilibrium values. The present theory indicates that undesired temperature-dependent shifting of sensor voltage curves with respect to engine air-fuel ratio is caused by competition between O/sub 2/ and CO gases for triple-point adsorption sites on the anode electrode. (13 fig, 3 tables.)

• Research Organization: General Motors Corp., Warren, MI
• OSTI ID: 7227036
• Journal Information: J. Electrochem. Soc.; (United States), Journal Name: J. Electrochem. Soc.; (United States) Vol. 124:1; ISSN JESOA
• Country of Publication: United States
• Language: English

Related Subjects

33 ADVANCED PROPULSION SYSTEMS
330700* -- Advanced Propulsion Systems-- Emission Control
36 MATERIALS SCIENCE
360200 -- Ceramics
Cermets
& Refractories
ADSORPTION
AUTOMOBILES
CARBON COMPOUNDS
CARBON MONOXIDE
CARBON OXIDES
CATALYSIS
CHALCOGENIDES
CHEMISTRY
CRYOGENIC FLUIDS
ELECTRICAL PROPERTIES
ELECTROCHEMISTRY
ELECTROLYTIC CELLS
ELEMENTS
EXHAUST GASES
FLUIDS
GASEOUS WASTES
MEASURING INSTRUMENTS
NONMETALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
SORPTION
TRANSITION ELEMENT COMPOUNDS
VEHICLES
WASTES
ZIRCONIUM COMPOUNDS
ZIRCONIUM OXIDES